[v9,08/13] media: atmel: atmel-isc: change format propagation to subdev into only verification

As a top MC video driver, the atmel-isc should not propagate the format to the
subdevice, it should rather check at start_streaming() time if the subdev is properly
configured with a compatible format.
Removed the whole format finding logic, and reworked the format verification
at start_streaming time, such that the ISC will return an error if the subdevice
is not properly configured. To achieve this, media_pipeline_start
is called and a link_validate callback is created to check the formats.
With this being done, the module parameter 'sensor_preferred' makes no sense
anymore. The ISC should not decide which format the sensor is using. The
ISC should only cope with the situation and inform userspace if the streaming
is possible in the current configuration.
The redesign of the format propagation has also risen the question of the
enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
should only return the formats that are supported for this mbus_code.
Otherwise, the enumfmt will report all the formats that the ISC could output.
With this rework, the dynamic list of user formats is removed. It makes no
more sense to identify at complete time which formats the sensor could emit,
and add those into a separate dynamic list.
The ISC will start with a simple preconfigured default format, and at
link validate time, decide whether it can use the format that is configured
on the sink or not.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
---
Changes in v9:
- isc_link_validate now static

Changes in v7:
- minor typos as suggested by Jacopo
- small changes, reduce some indentation, modified an index, as suggested by
Jacopo

Changes in v6:
- reworked a bit enum_fmt as suggested by Jacopo

Changes in v5:
- removed user_formats dynamic list as it is now pointless
- greatly simplified the enum_fmt function
- removed some init code that was useless now

Changes in v4:
- moved validation code into link_validate and used media_pipeline_start
- merged this patch with the enum_fmt patch which was previously in v3 of
the series

Changes in v3:
- clamp to maximum resolution once the frame size from the subdev is found
 drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
 .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
 drivers/media/platform/atmel/atmel-isc.h      |  13 +-
 .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
 .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
 5 files changed, 236 insertions(+), 234 deletions(-)

On 10/03/2022 10:51, Eugen Hristev wrote:
> As a top MC video driver, the atmel-isc should not propagate the format to the
> subdevice, it should rather check at start_streaming() time if the subdev is properly
> configured with a compatible format.
> Removed the whole format finding logic, and reworked the format verification
> at start_streaming time, such that the ISC will return an error if the subdevice
> is not properly configured. To achieve this, media_pipeline_start
> is called and a link_validate callback is created to check the formats.
> With this being done, the module parameter 'sensor_preferred' makes no sense
> anymore. The ISC should not decide which format the sensor is using. The
> ISC should only cope with the situation and inform userspace if the streaming
> is possible in the current configuration.
> The redesign of the format propagation has also risen the question of the
> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
> should only return the formats that are supported for this mbus_code.
> Otherwise, the enumfmt will report all the formats that the ISC could output.
> With this rework, the dynamic list of user formats is removed. It makes no
> more sense to identify at complete time which formats the sensor could emit,
> and add those into a separate dynamic list.
> The ISC will start with a simple preconfigured default format, and at
> link validate time, decide whether it can use the format that is configured
> on the sink or not.
> 
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> ---
> Changes in v9:
> - isc_link_validate now static
> 
> Changes in v7:
> - minor typos as suggested by Jacopo
> - small changes, reduce some indentation, modified an index, as suggested by
> Jacopo
> 
> Changes in v6:
> - reworked a bit enum_fmt as suggested by Jacopo
> 
> Changes in v5:
> - removed user_formats dynamic list as it is now pointless
> - greatly simplified the enum_fmt function
> - removed some init code that was useless now
> 
> Changes in v4:
> - moved validation code into link_validate and used media_pipeline_start
> - merged this patch with the enum_fmt patch which was previously in v3 of
> the series
> 
> Changes in v3:
> - clamp to maximum resolution once the frame size from the subdev is found
>  drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>  .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>  drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>  .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>  .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>  5 files changed, 236 insertions(+), 234 deletions(-)
> 
> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
> index ee1dda6707a0..fe2c0af58060 100644
> --- a/drivers/media/platform/atmel/atmel-isc-base.c
> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
> @@ -36,11 +36,6 @@ static unsigned int debug;
>  module_param(debug, int, 0644);
>  MODULE_PARM_DESC(debug, "debug level (0-2)");
>  
> -static unsigned int sensor_preferred = 1;
> -module_param(sensor_preferred, uint, 0644);
> -MODULE_PARM_DESC(sensor_preferred,
> -		 "Sensor is preferred to output the specified format (1-on 0-off), default 1");
> -
>  #define ISC_IS_FORMAT_RAW(mbus_code) \
>  	(((mbus_code) & 0xf000) == 0x3000)
>  
> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	unsigned long flags;
>  	int ret;
>  
> +	ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);

The pipeline validation is done in start_streaming, but I don't think that
is the best place: if STREAMON is called before buffers are queued, then
an invalid pipeline isn't discovered until enough buffers are queued to
kick off start_streaming.

Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().

I think that is the correct time to do this.

Laurent, Jacopo, do you agree with that?

I notice that quite a few other drivers do this in start_streaming as well,
but I think it just weird that a QBUF can return EPIPE while STREAMON might
succeed.

Perhaps we need an optional vb2 validate() callback that is called by
vb2_core_streamon() to validate the pipeline before streaming. That makes
it easier to implement these checks rather than having to implement your
own streamon ioctl.

Regards,

	Hans

> +	if (ret)
> +		goto err_pipeline_start;
> +
>  	/* Enable stream on the sub device */
>  	ret = v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 1);
>  	if (ret && ret != -ENOIOCTLCMD) {
> @@ -385,6 +384,9 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
>  
>  err_start_stream:
> +	media_pipeline_stop(&isc->video_dev.entity);
> +
> +err_pipeline_start:
>  	spin_lock_irqsave(&isc->dma_queue_lock, flags);
>  	list_for_each_entry(buf, &isc->dma_queue, list)
>  		vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
> @@ -423,6 +425,9 @@ static void isc_stop_streaming(struct vb2_queue *vq)
>  	if (ret && ret != -ENOIOCTLCMD)
>  		v4l2_err(&isc->v4l2_dev, "stream off failed in subdev\n");
>  
> +	/* Stop media pipeline */
> +	media_pipeline_stop(&isc->video_dev.entity);
> +
>  	/* Release all active buffers */
>  	spin_lock_irqsave(&isc->dma_queue_lock, flags);
>  	if (unlikely(isc->cur_frm)) {
> @@ -453,22 +458,6 @@ static void isc_buffer_queue(struct vb2_buffer *vb)
>  	spin_unlock_irqrestore(&isc->dma_queue_lock, flags);
>  }
>  
> -static struct isc_format *find_format_by_fourcc(struct isc_device *isc,
> -						 unsigned int fourcc)
> -{
> -	unsigned int num_formats = isc->num_user_formats;
> -	struct isc_format *fmt;
> -	unsigned int i;
> -
> -	for (i = 0; i < num_formats; i++) {
> -		fmt = isc->user_formats[i];
> -		if (fmt->fourcc == fourcc)
> -			return fmt;
> -	}
> -
> -	return NULL;
> -}
> -
>  static const struct vb2_ops isc_vb2_ops = {
>  	.queue_setup		= isc_queue_setup,
>  	.wait_prepare		= vb2_ops_wait_prepare,
> @@ -497,23 +486,57 @@ static int isc_enum_fmt_vid_cap(struct file *file, void *priv,
>  {
>  	struct isc_device *isc = video_drvdata(file);
>  	u32 index = f->index;
> -	u32 i, supported_index;
> +	u32 i, supported_index = 0;
> +	struct isc_format *fmt;
> +
> +	/*
> +	 * If we are not asked a specific mbus_code, we have to report all
> +	 * the formats that we can output.
> +	 */
> +	if (!f->mbus_code) {
> +		if (index >= isc->controller_formats_size)
> +			return -EINVAL;
>  
> -	if (index < isc->controller_formats_size) {
>  		f->pixelformat = isc->controller_formats[index].fourcc;
> +
> +		return 0;
> +	}
> +
> +	/*
> +	 * If a specific mbus_code is requested, check if we support
> +	 * this mbus_code as input for the ISC.
> +	 * If it's supported, then we report the corresponding pixelformat
> +	 * as first possible option for the ISC.
> +	 * E.g. mbus MEDIA_BUS_FMT_YUYV8_2X8 and report
> +	 * 'YUYV' (YUYV 4:2:2)
> +	 */
> +	fmt = isc_find_format_by_code(isc, f->mbus_code, &i);
> +	if (!fmt)
> +		return -EINVAL;
> +
> +	if (!index) {
> +		f->pixelformat = fmt->fourcc;
> +
>  		return 0;
>  	}
>  
> -	index -= isc->controller_formats_size;
> +	supported_index++;
>  
> -	supported_index = 0;
> +	/* If the index is not raw, we don't have anymore formats to report */
> +	if (!ISC_IS_FORMAT_RAW(f->mbus_code))
> +		return -EINVAL;
>  
> -	for (i = 0; i < isc->formats_list_size; i++) {
> -		if (!ISC_IS_FORMAT_RAW(isc->formats_list[i].mbus_code) ||
> -		    !isc->formats_list[i].sd_support)
> +	/*
> +	 * We are asked for a specific mbus code, which is raw.
> +	 * We have to search through the formats we can convert to.
> +	 * We have to skip the raw formats, we cannot convert to raw.
> +	 * E.g. 'AR12' (16-bit ARGB 4-4-4-4), 'AR15' (16-bit ARGB 1-5-5-5), etc.
> +	 */
> +	for (i = 0; i < isc->controller_formats_size; i++) {
> +		if (isc->controller_formats[i].raw)
>  			continue;
> -		if (supported_index == index) {
> -			f->pixelformat = isc->formats_list[i].fourcc;
> +		if (index == supported_index) {
> +			f->pixelformat = isc->controller_formats[i].fourcc;
>  			return 0;
>  		}
>  		supported_index++;
> @@ -584,20 +607,30 @@ static int isc_try_validate_formats(struct isc_device *isc)
>  		break;
>  	default:
>  	/* any other different formats are not supported */
> +		v4l2_err(&isc->v4l2_dev, "Requested unsupported format.\n");
>  		ret = -EINVAL;
>  	}
>  	v4l2_dbg(1, debug, &isc->v4l2_dev,
>  		 "Format validation, requested rgb=%u, yuv=%u, grey=%u, bayer=%u\n",
>  		 rgb, yuv, grey, bayer);
>  
> -	/* we cannot output RAW if we do not receive RAW */
> -	if ((bayer) && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
> +	if (bayer &&
> +	    !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code)) {
> +		v4l2_err(&isc->v4l2_dev, "Cannot output RAW if we do not receive RAW.\n");
>  		return -EINVAL;
> +	}
>  
> -	/* we cannot output GREY if we do not receive RAW/GREY */
>  	if (grey && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code) &&
> -	    !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code))
> +	    !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
> +		v4l2_err(&isc->v4l2_dev, "Cannot output GREY if we do not receive RAW/GREY.\n");
>  		return -EINVAL;
> +	}
> +
> +	if ((rgb || bayer || yuv) &&
> +	    ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
> +		v4l2_err(&isc->v4l2_dev, "Cannot convert GREY to another format.\n");
> +		return -EINVAL;
> +	}
>  
>  	return ret;
>  }
> @@ -825,7 +858,7 @@ static void isc_try_fse(struct isc_device *isc,
>  	 * If we do not know yet which format the subdev is using, we cannot
>  	 * do anything.
>  	 */
> -	if (!isc->try_config.sd_format)
> +	if (!isc->config.sd_format)
>  		return;
>  
>  	fse.code = isc->try_config.sd_format->mbus_code;
> @@ -846,180 +879,140 @@ static void isc_try_fse(struct isc_device *isc,
>  	}
>  }
>  
> -static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
> -			u32 *code)
> +static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f)
>  {
> -	int i;
> -	struct isc_format *sd_fmt = NULL, *direct_fmt = NULL;
>  	struct v4l2_pix_format *pixfmt = &f->fmt.pix;
> -	struct v4l2_subdev_pad_config pad_cfg = {};
> -	struct v4l2_subdev_state pad_state = {
> -		.pads = &pad_cfg
> -		};
> -	struct v4l2_subdev_format format = {
> -		.which = V4L2_SUBDEV_FORMAT_TRY,
> -	};
> -	u32 mbus_code;
> -	int ret;
> -	bool rlp_dma_direct_dump = false;
> +	unsigned int i;
>  
>  	if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>  		return -EINVAL;
>  
> -	/* Step 1: find a RAW format that is supported */
> -	for (i = 0; i < isc->num_user_formats; i++) {
> -		if (ISC_IS_FORMAT_RAW(isc->user_formats[i]->mbus_code)) {
> -			sd_fmt = isc->user_formats[i];
> +	isc->try_config.fourcc = isc->controller_formats[0].fourcc;
> +
> +	/* find if the format requested is supported */
> +	for (i = 0; i < isc->controller_formats_size; i++)
> +		if (isc->controller_formats[i].fourcc == pixfmt->pixelformat) {
> +			isc->try_config.fourcc = pixfmt->pixelformat;
>  			break;
>  		}
> -	}
> -	/* Step 2: We can continue with this RAW format, or we can look
> -	 * for better: maybe sensor supports directly what we need.
> -	 */
> -	direct_fmt = find_format_by_fourcc(isc, pixfmt->pixelformat);
> -
> -	/* Step 3: We have both. We decide given the module parameter which
> -	 * one to use.
> -	 */
> -	if (direct_fmt && sd_fmt && sensor_preferred)
> -		sd_fmt = direct_fmt;
> -
> -	/* Step 4: we do not have RAW but we have a direct format. Use it. */
> -	if (direct_fmt && !sd_fmt)
> -		sd_fmt = direct_fmt;
> -
> -	/* Step 5: if we are using a direct format, we need to package
> -	 * everything as 8 bit data and just dump it
> -	 */
> -	if (sd_fmt == direct_fmt)
> -		rlp_dma_direct_dump = true;
> -
> -	/* Step 6: We have no format. This can happen if the userspace
> -	 * requests some weird/invalid format.
> -	 * In this case, default to whatever we have
> -	 */
> -	if (!sd_fmt && !direct_fmt) {
> -		sd_fmt = isc->user_formats[isc->num_user_formats - 1];
> -		v4l2_dbg(1, debug, &isc->v4l2_dev,
> -			 "Sensor not supporting %.4s, using %.4s\n",
> -			 (char *)&pixfmt->pixelformat, (char *)&sd_fmt->fourcc);
> -	}
> -
> -	if (!sd_fmt) {
> -		ret = -EINVAL;
> -		goto isc_try_fmt_err;
> -	}
> -
> -	/* Step 7: Print out what we decided for debugging */
> -	v4l2_dbg(1, debug, &isc->v4l2_dev,
> -		 "Preferring to have sensor using format %.4s\n",
> -		 (char *)&sd_fmt->fourcc);
>  
> -	/* Step 8: at this moment we decided which format the subdev will use */
> -	isc->try_config.sd_format = sd_fmt;
> +	isc_try_configure_rlp_dma(isc, false);
>  
>  	/* Limit to Atmel ISC hardware capabilities */
> -	if (pixfmt->width > isc->max_width)
> -		pixfmt->width = isc->max_width;
> -	if (pixfmt->height > isc->max_height)
> -		pixfmt->height = isc->max_height;
> -
> -	/*
> -	 * The mbus format is the one the subdev outputs.
> -	 * The pixels will be transferred in this format Sensor -> ISC
> -	 */
> -	mbus_code = sd_fmt->mbus_code;
> -
> -	/*
> -	 * Validate formats. If the required format is not OK, default to raw.
> -	 */
> -
> -	isc->try_config.fourcc = pixfmt->pixelformat;
> -
> -	if (isc_try_validate_formats(isc)) {
> -		pixfmt->pixelformat = isc->try_config.fourcc = sd_fmt->fourcc;
> -		/* Re-try to validate the new format */
> -		ret = isc_try_validate_formats(isc);
> -		if (ret)
> -			goto isc_try_fmt_err;
> -	}
> -
> -	ret = isc_try_configure_rlp_dma(isc, rlp_dma_direct_dump);
> -	if (ret)
> -		goto isc_try_fmt_err;
> -
> -	ret = isc_try_configure_pipeline(isc);
> -	if (ret)
> -		goto isc_try_fmt_err;
> -
> -	/* Obtain frame sizes if possible to have crop requirements ready */
> -	isc_try_fse(isc, &pad_state);
> -
> -	v4l2_fill_mbus_format(&format.format, pixfmt, mbus_code);
> -	ret = v4l2_subdev_call(isc->current_subdev->sd, pad, set_fmt,
> -			       &pad_state, &format);
> -	if (ret < 0)
> -		goto isc_try_fmt_subdev_err;
> -
> -	v4l2_fill_pix_format(pixfmt, &format.format);
> +	v4l_bound_align_image(&pixfmt->width, 16, isc->max_width, 0,
> +			      &pixfmt->height, 16, isc->max_height, 0, 0);
> +	/* If we did not find the requested format, we will fallback here */
> +	pixfmt->pixelformat = isc->try_config.fourcc;
> +	pixfmt->colorspace = V4L2_COLORSPACE_SRGB;
> +	pixfmt->field = V4L2_FIELD_NONE;
>  
> -	/* Limit to Atmel ISC hardware capabilities */
> -	if (pixfmt->width > isc->max_width)
> -		pixfmt->width = isc->max_width;
> -	if (pixfmt->height > isc->max_height)
> -		pixfmt->height = isc->max_height;
>  
> -	pixfmt->field = V4L2_FIELD_NONE;
>  	pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
>  	pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
>  			     pixfmt->height;
>  
> -	if (code)
> -		*code = mbus_code;
> +	isc->try_fmt = *f;
>  
>  	return 0;
> +}
>  
> -isc_try_fmt_err:
> -	v4l2_err(&isc->v4l2_dev, "Could not find any possible format for a working pipeline\n");
> -isc_try_fmt_subdev_err:
> -	memset(&isc->try_config, 0, sizeof(isc->try_config));
> +static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
> +{
> +	isc_try_fmt(isc, f);
>  
> -	return ret;
> +	/* make the try configuration active */
> +	isc->config = isc->try_config;
> +	isc->fmt = isc->try_fmt;
> +
> +	v4l2_dbg(1, debug, &isc->v4l2_dev, "ISC set_fmt to %.4s @%dx%d\n",
> +		 (char *)&f->fmt.pix.pixelformat,
> +		 f->fmt.pix.width, f->fmt.pix.height);
> +
> +	return 0;
>  }
>  
> -static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
> +static int isc_validate(struct isc_device *isc)
>  {
> +	int ret;
> +	int i;
> +	struct isc_format *sd_fmt = NULL;
> +	struct v4l2_pix_format *pixfmt = &isc->fmt.fmt.pix;
>  	struct v4l2_subdev_format format = {
>  		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
> +		.pad = isc->remote_pad,
> +	};
> +	struct v4l2_subdev_pad_config pad_cfg = {};
> +	struct v4l2_subdev_state pad_state = {
> +		.pads = &pad_cfg,
>  	};
> -	u32 mbus_code = 0;
> -	int ret;
>  
> -	ret = isc_try_fmt(isc, f, &mbus_code);
> +	/* Get current format from subdev */
> +	ret = v4l2_subdev_call(isc->current_subdev->sd, pad, get_fmt, NULL,
> +			       &format);
>  	if (ret)
>  		return ret;
>  
> -	v4l2_fill_mbus_format(&format.format, &f->fmt.pix, mbus_code);
> -	ret = v4l2_subdev_call(isc->current_subdev->sd, pad,
> -			       set_fmt, NULL, &format);
> -	if (ret < 0)
> -		return ret;
> +	/* Identify the subdev's format configuration */
> +	for (i = 0; i < isc->formats_list_size; i++)
> +		if (isc->formats_list[i].mbus_code == format.format.code) {
> +			sd_fmt = &isc->formats_list[i];
> +			break;
> +		}
> +
> +	/* Check if the format is not supported */
> +	if (!sd_fmt) {
> +		v4l2_err(&isc->v4l2_dev,
> +			 "Current subdevice is streaming a media bus code that is not supported 0x%x\n",
> +			 format.format.code);
> +		return -EPIPE;
> +	}
> +
> +	/* At this moment we know which format the subdev will use */
> +	isc->try_config.sd_format = sd_fmt;
> +
> +	/* If the sensor is not RAW, we can only do a direct dump */
> +	if (!ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
> +		isc_try_configure_rlp_dma(isc, true);
>  
>  	/* Limit to Atmel ISC hardware capabilities */
> -	if (f->fmt.pix.width > isc->max_width)
> -		f->fmt.pix.width = isc->max_width;
> -	if (f->fmt.pix.height > isc->max_height)
> -		f->fmt.pix.height = isc->max_height;
> +	v4l_bound_align_image(&format.format.width, 16, isc->max_width, 0,
> +			      &format.format.height, 16, isc->max_height, 0, 0);
>  
> -	isc->fmt = *f;
> +	/* Check if the frame size is the same. Otherwise we may overflow */
> +	if (pixfmt->height != format.format.height ||
> +	    pixfmt->width != format.format.width) {
> +		v4l2_err(&isc->v4l2_dev,
> +			 "ISC not configured with the proper frame size: %dx%d\n",
> +			 format.format.width, format.format.height);
> +		return -EPIPE;
> +	}
>  
> +	v4l2_dbg(1, debug, &isc->v4l2_dev,
> +		 "Identified subdev using format %.4s with %dx%d %d bpp\n",
> +		 (char *)&sd_fmt->fourcc, pixfmt->width, pixfmt->height,
> +		 isc->try_config.bpp);
> +
> +	/* Reset and restart AWB if the subdevice changed the format */
>  	if (isc->try_config.sd_format && isc->config.sd_format &&
>  	    isc->try_config.sd_format != isc->config.sd_format) {
>  		isc->ctrls.hist_stat = HIST_INIT;
>  		isc_reset_awb_ctrls(isc);
>  		isc_update_v4l2_ctrls(isc);
>  	}
> -	/* make the try configuration active */
> +
> +	/* Validate formats */
> +	ret = isc_try_validate_formats(isc);
> +	if (ret)
> +		return ret;
> +
> +	/* Obtain frame sizes if possible to have crop requirements ready */
> +	isc_try_fse(isc, &pad_state);
> +
> +	/* Configure ISC pipeline for the config */
> +	ret = isc_try_configure_pipeline(isc);
> +	if (ret)
> +		return ret;
> +
>  	isc->config = isc->try_config;
>  
>  	v4l2_dbg(1, debug, &isc->v4l2_dev, "New ISC configuration in place\n");
> @@ -1043,7 +1036,7 @@ static int isc_try_fmt_vid_cap(struct file *file, void *priv,
>  {
>  	struct isc_device *isc = video_drvdata(file);
>  
> -	return isc_try_fmt(isc, f, NULL);
> +	return isc_try_fmt(isc, f);
>  }
>  
>  static int isc_enum_input(struct file *file, void *priv,
> @@ -1098,10 +1091,6 @@ static int isc_enum_framesizes(struct file *file, void *fh,
>  	if (fsize->index)
>  		return -EINVAL;
>  
> -	for (i = 0; i < isc->num_user_formats; i++)
> -		if (isc->user_formats[i]->fourcc == fsize->pixel_format)
> -			ret = 0;
> -
>  	for (i = 0; i < isc->controller_formats_size; i++)
>  		if (isc->controller_formats[i].fourcc == fsize->pixel_format)
>  			ret = 0;
> @@ -1782,52 +1771,6 @@ struct isc_format *isc_find_format_by_code(struct isc_device *isc,
>  }
>  EXPORT_SYMBOL_GPL(isc_find_format_by_code);
>  
> -static int isc_formats_init(struct isc_device *isc)
> -{
> -	struct isc_format *fmt;
> -	struct v4l2_subdev *subdev = isc->current_subdev->sd;
> -	unsigned int num_fmts, i, j;
> -	u32 list_size = isc->formats_list_size;
> -	struct v4l2_subdev_mbus_code_enum mbus_code = {
> -		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
> -	};
> -
> -	num_fmts = 0;
> -	while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
> -	       NULL, &mbus_code)) {
> -		mbus_code.index++;
> -
> -		fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
> -		if (!fmt) {
> -			v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
> -				  mbus_code.code);
> -			continue;
> -		}
> -
> -		fmt->sd_support = true;
> -		num_fmts++;
> -	}
> -
> -	if (!num_fmts)
> -		return -ENXIO;
> -
> -	isc->num_user_formats = num_fmts;
> -	isc->user_formats = devm_kcalloc(isc->dev,
> -					 num_fmts, sizeof(*isc->user_formats),
> -					 GFP_KERNEL);
> -	if (!isc->user_formats)
> -		return -ENOMEM;
> -
> -	fmt = &isc->formats_list[0];
> -	for (i = 0, j = 0; i < list_size; i++) {
> -		if (fmt->sd_support)
> -			isc->user_formats[j++] = fmt;
> -		fmt++;
> -	}
> -
> -	return 0;
> -}
> -
>  static int isc_set_default_fmt(struct isc_device *isc)
>  {
>  	struct v4l2_format f = {
> @@ -1836,12 +1779,12 @@ static int isc_set_default_fmt(struct isc_device *isc)
>  			.width		= VGA_WIDTH,
>  			.height		= VGA_HEIGHT,
>  			.field		= V4L2_FIELD_NONE,
> -			.pixelformat	= isc->user_formats[0]->fourcc,
> +			.pixelformat	= isc->controller_formats[0].fourcc,
>  		},
>  	};
>  	int ret;
>  
> -	ret = isc_try_fmt(isc, &f, NULL);
> +	ret = isc_try_fmt(isc, &f);
>  	if (ret)
>  		return ret;
>  
> @@ -1896,13 +1839,6 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
>  	spin_lock_init(&isc->dma_queue_lock);
>  	spin_lock_init(&isc->awb_lock);
>  
> -	ret = isc_formats_init(isc);
> -	if (ret < 0) {
> -		v4l2_err(&isc->v4l2_dev,
> -			 "Init format failed: %d\n", ret);
> -		goto isc_async_complete_err;
> -	}
> -
>  	ret = isc_set_default_fmt(isc);
>  	if (ret) {
>  		v4l2_err(&isc->v4l2_dev, "Could not set default format\n");
> @@ -2016,6 +1952,24 @@ int isc_pipeline_init(struct isc_device *isc)
>  }
>  EXPORT_SYMBOL_GPL(isc_pipeline_init);
>  
> +static int isc_link_validate(struct media_link *link)
> +{
> +	struct video_device *vdev =
> +		media_entity_to_video_device(link->sink->entity);
> +	struct isc_device *isc = video_get_drvdata(vdev);
> +	int ret;
> +
> +	ret = v4l2_subdev_link_validate(link);
> +	if (ret)
> +		return ret;
> +
> +	return isc_validate(isc);
> +}
> +
> +static const struct media_entity_operations isc_entity_operations = {
> +	.link_validate = isc_link_validate,
> +};
> +
>  int isc_mc_init(struct isc_device *isc, u32 ver)
>  {
>  	const struct of_device_id *match;
> @@ -2023,6 +1977,8 @@ int isc_mc_init(struct isc_device *isc, u32 ver)
>  
>  	isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
>  	isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
> +	isc->video_dev.entity.ops = &isc_entity_operations;
> +
>  	isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>  
>  	ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
> diff --git a/drivers/media/platform/atmel/atmel-isc-scaler.c b/drivers/media/platform/atmel/atmel-isc-scaler.c
> index a1ca4633787c..2b0621297dfe 100644
> --- a/drivers/media/platform/atmel/atmel-isc-scaler.c
> +++ b/drivers/media/platform/atmel/atmel-isc-scaler.c
> @@ -173,6 +173,10 @@ static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
>  	.init_cfg = isc_scaler_init_cfg,
>  };
>  
> +static const struct media_entity_operations isc_scaler_entity_ops = {
> +	.link_validate = v4l2_subdev_link_validate,
> +};
> +
>  static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
>  	.pad = &isc_scaler_pad_ops,
>  };
> @@ -190,6 +194,7 @@ int isc_scaler_init(struct isc_device *isc)
>  
>  	isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>  	isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
> +	isc->scaler_sd.entity.ops = &isc_scaler_entity_ops;
>  	isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>  	isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
>  
> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
> index f98f25a55e73..5b0100c8c245 100644
> --- a/drivers/media/platform/atmel/atmel-isc.h
> +++ b/drivers/media/platform/atmel/atmel-isc.h
> @@ -63,15 +63,16 @@ struct isc_subdev_entity {
>   * @cfa_baycfg:		If this format is RAW BAYER, indicate the type of bayer.
>  			this is either BGBG, RGRG, etc.
>   * @pfe_cfg0_bps:	Number of hardware data lines connected to the ISC
> + * @raw:		If the format is raw bayer.
>   */
>  
>  struct isc_format {
>  	u32	fourcc;
>  	u32	mbus_code;
>  	u32	cfa_baycfg;
> -
> -	bool	sd_support;
>  	u32	pfe_cfg0_bps;
> +
> +	bool	raw;
>  };
>  
>  /* Pipeline bitmap */
> @@ -216,8 +217,7 @@ enum isc_scaler_pads {
>   * @comp:		completion reference that signals frame completion
>   *
>   * @fmt:		current v42l format
> - * @user_formats:	list of formats that are supported and agreed with sd
> - * @num_user_formats:	how many formats are in user_formats
> + * @try_fmt:		current v4l2 try format
>   *
>   * @config:		current ISC format configuration
>   * @try_config:		the current ISC try format , not yet activated
> @@ -272,6 +272,7 @@ enum isc_scaler_pads {
>   * @formats_list_size:	size of formats_list array
>   * @pads:		media controller pads for isc video entity
>   * @mdev:		media device that is registered by the isc
> + * @mpipe:		media device pipeline used by the isc
>   * @remote_pad:		remote pad on the connected subdevice
>   * @scaler_sd:		subdevice for the scaler that isc registers
>   * @scaler_pads:	media controller pads for the scaler subdevice
> @@ -298,8 +299,7 @@ struct isc_device {
>  	struct completion	comp;
>  
>  	struct v4l2_format	fmt;
> -	struct isc_format	**user_formats;
> -	unsigned int		num_user_formats;
> +	struct v4l2_format	try_fmt;
>  
>  	struct fmt_config	config;
>  	struct fmt_config	try_config;
> @@ -369,6 +369,7 @@ struct isc_device {
>  	struct {
>  		struct media_pad		pads[ISC_PADS_NUM];
>  		struct media_device		mdev;
> +		struct media_pipeline		mpipe;
>  
>  		u32				remote_pad;
>  	};
> diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> index d96ee3373889..2a651e237193 100644
> --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> @@ -80,20 +80,40 @@ static const struct isc_format sama5d2_controller_formats[] = {
>  		.fourcc		= V4L2_PIX_FMT_Y10,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SBGGR8,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SGBRG8,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SGRBG8,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SRGGB8,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SBGGR10,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SGBRG10,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SGRBG10,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SRGGB10,
> +		.raw		= true,
> +	}, {
> +		.fourcc		= V4L2_PIX_FMT_SBGGR12,
> +		.raw		= true,
> +	}, {
> +		.fourcc		= V4L2_PIX_FMT_SGBRG12,
> +		.raw		= true,
> +	}, {
> +		.fourcc		= V4L2_PIX_FMT_SGRBG12,
> +		.raw		= true,
> +	}, {
> +		.fourcc		= V4L2_PIX_FMT_SRGGB12,
> +		.raw		= true,
>  	},
>  };
>  
> diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> index e07ae188c15f..a0d60cfdba7b 100644
> --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> @@ -89,20 +89,40 @@ static const struct isc_format sama7g5_controller_formats[] = {
>  		.fourcc		= V4L2_PIX_FMT_Y16,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SBGGR8,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SGBRG8,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SGRBG8,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SRGGB8,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SBGGR10,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SGBRG10,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SGRBG10,
> +		.raw		= true,
>  	}, {
>  		.fourcc		= V4L2_PIX_FMT_SRGGB10,
> +		.raw		= true,
> +	}, {
> +		.fourcc		= V4L2_PIX_FMT_SBGGR12,
> +		.raw		= true,
> +	}, {
> +		.fourcc		= V4L2_PIX_FMT_SGBRG12,
> +		.raw		= true,
> +	}, {
> +		.fourcc		= V4L2_PIX_FMT_SGRBG12,
> +		.raw		= true,
> +	}, {
> +		.fourcc		= V4L2_PIX_FMT_SRGGB12,
> +		.raw		= true,
>  	},
>  };
>

On 4/29/22 11:17 AM, Hans Verkuil wrote:
> On 10/03/2022 10:51, Eugen Hristev wrote:
>> As a top MC video driver, the atmel-isc should not propagate the format to the
>> subdevice, it should rather check at start_streaming() time if the subdev is properly
>> configured with a compatible format.
>> Removed the whole format finding logic, and reworked the format verification
>> at start_streaming time, such that the ISC will return an error if the subdevice
>> is not properly configured. To achieve this, media_pipeline_start
>> is called and a link_validate callback is created to check the formats.
>> With this being done, the module parameter 'sensor_preferred' makes no sense
>> anymore. The ISC should not decide which format the sensor is using. The
>> ISC should only cope with the situation and inform userspace if the streaming
>> is possible in the current configuration.
>> The redesign of the format propagation has also risen the question of the
>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
>> should only return the formats that are supported for this mbus_code.
>> Otherwise, the enumfmt will report all the formats that the ISC could output.
>> With this rework, the dynamic list of user formats is removed. It makes no
>> more sense to identify at complete time which formats the sensor could emit,
>> and add those into a separate dynamic list.
>> The ISC will start with a simple preconfigured default format, and at
>> link validate time, decide whether it can use the format that is configured
>> on the sink or not.
>>
>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>> ---
>> Changes in v9:
>> - isc_link_validate now static
>>
>> Changes in v7:
>> - minor typos as suggested by Jacopo
>> - small changes, reduce some indentation, modified an index, as suggested by
>> Jacopo
>>
>> Changes in v6:
>> - reworked a bit enum_fmt as suggested by Jacopo
>>
>> Changes in v5:
>> - removed user_formats dynamic list as it is now pointless
>> - greatly simplified the enum_fmt function
>> - removed some init code that was useless now
>>
>> Changes in v4:
>> - moved validation code into link_validate and used media_pipeline_start
>> - merged this patch with the enum_fmt patch which was previously in v3 of
>> the series
>>
>> Changes in v3:
>> - clamp to maximum resolution once the frame size from the subdev is found
>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>>   5 files changed, 236 insertions(+), 234 deletions(-)
>>
>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>> index ee1dda6707a0..fe2c0af58060 100644
>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>> @@ -36,11 +36,6 @@ static unsigned int debug;
>>   module_param(debug, int, 0644);
>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
>>
>> -static unsigned int sensor_preferred = 1;
>> -module_param(sensor_preferred, uint, 0644);
>> -MODULE_PARM_DESC(sensor_preferred,
>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>> -
>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
>>        (((mbus_code) & 0xf000) == 0x3000)
>>
>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>        unsigned long flags;
>>        int ret;
>>
>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
> 
> The pipeline validation is done in start_streaming, but I don't think that
> is the best place: if STREAMON is called before buffers are queued, then
> an invalid pipeline isn't discovered until enough buffers are queued to
> kick off start_streaming.
> 
> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
> 
> I think that is the correct time to do this.

Hello Hans,

Initially (v2, v3) I had this in streamon(). The problem that I faced at 
that time was that streamoff was never called, so I could not call 
media_pipeline_stop(). Then Jacopo told me to move it to start_streaming 
(see change log for v4) , and I did not face any more problems.

Eugen

> 
> Laurent, Jacopo, do you agree with that?
> 
> I notice that quite a few other drivers do this in start_streaming as well,
> but I think it just weird that a QBUF can return EPIPE while STREAMON might
> succeed.
> 
> Perhaps we need an optional vb2 validate() callback that is called by
> vb2_core_streamon() to validate the pipeline before streaming. That makes
> it easier to implement these checks rather than having to implement your
> own streamon ioctl.
> 
> Regards,
> 
>          Hans
> 
>> +     if (ret)
>> +             goto err_pipeline_start;
>> +
>>        /* Enable stream on the sub device */
>>        ret = v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 1);
>>        if (ret && ret != -ENOIOCTLCMD) {
>> @@ -385,6 +384,9 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>        v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
>>
>>   err_start_stream:
>> +     media_pipeline_stop(&isc->video_dev.entity);
>> +
>> +err_pipeline_start:
>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
>>        list_for_each_entry(buf, &isc->dma_queue, list)
>>                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
>> @@ -423,6 +425,9 @@ static void isc_stop_streaming(struct vb2_queue *vq)
>>        if (ret && ret != -ENOIOCTLCMD)
>>                v4l2_err(&isc->v4l2_dev, "stream off failed in subdev\n");
>>
>> +     /* Stop media pipeline */
>> +     media_pipeline_stop(&isc->video_dev.entity);
>> +
>>        /* Release all active buffers */
>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
>>        if (unlikely(isc->cur_frm)) {
>> @@ -453,22 +458,6 @@ static void isc_buffer_queue(struct vb2_buffer *vb)
>>        spin_unlock_irqrestore(&isc->dma_queue_lock, flags);
>>   }
>>
>> -static struct isc_format *find_format_by_fourcc(struct isc_device *isc,
>> -                                              unsigned int fourcc)
>> -{
>> -     unsigned int num_formats = isc->num_user_formats;
>> -     struct isc_format *fmt;
>> -     unsigned int i;
>> -
>> -     for (i = 0; i < num_formats; i++) {
>> -             fmt = isc->user_formats[i];
>> -             if (fmt->fourcc == fourcc)
>> -                     return fmt;
>> -     }
>> -
>> -     return NULL;
>> -}
>> -
>>   static const struct vb2_ops isc_vb2_ops = {
>>        .queue_setup            = isc_queue_setup,
>>        .wait_prepare           = vb2_ops_wait_prepare,
>> @@ -497,23 +486,57 @@ static int isc_enum_fmt_vid_cap(struct file *file, void *priv,
>>   {
>>        struct isc_device *isc = video_drvdata(file);
>>        u32 index = f->index;
>> -     u32 i, supported_index;
>> +     u32 i, supported_index = 0;
>> +     struct isc_format *fmt;
>> +
>> +     /*
>> +      * If we are not asked a specific mbus_code, we have to report all
>> +      * the formats that we can output.
>> +      */
>> +     if (!f->mbus_code) {
>> +             if (index >= isc->controller_formats_size)
>> +                     return -EINVAL;
>>
>> -     if (index < isc->controller_formats_size) {
>>                f->pixelformat = isc->controller_formats[index].fourcc;
>> +
>> +             return 0;
>> +     }
>> +
>> +     /*
>> +      * If a specific mbus_code is requested, check if we support
>> +      * this mbus_code as input for the ISC.
>> +      * If it's supported, then we report the corresponding pixelformat
>> +      * as first possible option for the ISC.
>> +      * E.g. mbus MEDIA_BUS_FMT_YUYV8_2X8 and report
>> +      * 'YUYV' (YUYV 4:2:2)
>> +      */
>> +     fmt = isc_find_format_by_code(isc, f->mbus_code, &i);
>> +     if (!fmt)
>> +             return -EINVAL;
>> +
>> +     if (!index) {
>> +             f->pixelformat = fmt->fourcc;
>> +
>>                return 0;
>>        }
>>
>> -     index -= isc->controller_formats_size;
>> +     supported_index++;
>>
>> -     supported_index = 0;
>> +     /* If the index is not raw, we don't have anymore formats to report */
>> +     if (!ISC_IS_FORMAT_RAW(f->mbus_code))
>> +             return -EINVAL;
>>
>> -     for (i = 0; i < isc->formats_list_size; i++) {
>> -             if (!ISC_IS_FORMAT_RAW(isc->formats_list[i].mbus_code) ||
>> -                 !isc->formats_list[i].sd_support)
>> +     /*
>> +      * We are asked for a specific mbus code, which is raw.
>> +      * We have to search through the formats we can convert to.
>> +      * We have to skip the raw formats, we cannot convert to raw.
>> +      * E.g. 'AR12' (16-bit ARGB 4-4-4-4), 'AR15' (16-bit ARGB 1-5-5-5), etc.
>> +      */
>> +     for (i = 0; i < isc->controller_formats_size; i++) {
>> +             if (isc->controller_formats[i].raw)
>>                        continue;
>> -             if (supported_index == index) {
>> -                     f->pixelformat = isc->formats_list[i].fourcc;
>> +             if (index == supported_index) {
>> +                     f->pixelformat = isc->controller_formats[i].fourcc;
>>                        return 0;
>>                }
>>                supported_index++;
>> @@ -584,20 +607,30 @@ static int isc_try_validate_formats(struct isc_device *isc)
>>                break;
>>        default:
>>        /* any other different formats are not supported */
>> +             v4l2_err(&isc->v4l2_dev, "Requested unsupported format.\n");
>>                ret = -EINVAL;
>>        }
>>        v4l2_dbg(1, debug, &isc->v4l2_dev,
>>                 "Format validation, requested rgb=%u, yuv=%u, grey=%u, bayer=%u\n",
>>                 rgb, yuv, grey, bayer);
>>
>> -     /* we cannot output RAW if we do not receive RAW */
>> -     if ((bayer) && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>> +     if (bayer &&
>> +         !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code)) {
>> +             v4l2_err(&isc->v4l2_dev, "Cannot output RAW if we do not receive RAW.\n");
>>                return -EINVAL;
>> +     }
>>
>> -     /* we cannot output GREY if we do not receive RAW/GREY */
>>        if (grey && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code) &&
>> -         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code))
>> +         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>> +             v4l2_err(&isc->v4l2_dev, "Cannot output GREY if we do not receive RAW/GREY.\n");
>>                return -EINVAL;
>> +     }
>> +
>> +     if ((rgb || bayer || yuv) &&
>> +         ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>> +             v4l2_err(&isc->v4l2_dev, "Cannot convert GREY to another format.\n");
>> +             return -EINVAL;
>> +     }
>>
>>        return ret;
>>   }
>> @@ -825,7 +858,7 @@ static void isc_try_fse(struct isc_device *isc,
>>         * If we do not know yet which format the subdev is using, we cannot
>>         * do anything.
>>         */
>> -     if (!isc->try_config.sd_format)
>> +     if (!isc->config.sd_format)
>>                return;
>>
>>        fse.code = isc->try_config.sd_format->mbus_code;
>> @@ -846,180 +879,140 @@ static void isc_try_fse(struct isc_device *isc,
>>        }
>>   }
>>
>> -static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
>> -                     u32 *code)
>> +static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f)
>>   {
>> -     int i;
>> -     struct isc_format *sd_fmt = NULL, *direct_fmt = NULL;
>>        struct v4l2_pix_format *pixfmt = &f->fmt.pix;
>> -     struct v4l2_subdev_pad_config pad_cfg = {};
>> -     struct v4l2_subdev_state pad_state = {
>> -             .pads = &pad_cfg
>> -             };
>> -     struct v4l2_subdev_format format = {
>> -             .which = V4L2_SUBDEV_FORMAT_TRY,
>> -     };
>> -     u32 mbus_code;
>> -     int ret;
>> -     bool rlp_dma_direct_dump = false;
>> +     unsigned int i;
>>
>>        if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>>                return -EINVAL;
>>
>> -     /* Step 1: find a RAW format that is supported */
>> -     for (i = 0; i < isc->num_user_formats; i++) {
>> -             if (ISC_IS_FORMAT_RAW(isc->user_formats[i]->mbus_code)) {
>> -                     sd_fmt = isc->user_formats[i];
>> +     isc->try_config.fourcc = isc->controller_formats[0].fourcc;
>> +
>> +     /* find if the format requested is supported */
>> +     for (i = 0; i < isc->controller_formats_size; i++)
>> +             if (isc->controller_formats[i].fourcc == pixfmt->pixelformat) {
>> +                     isc->try_config.fourcc = pixfmt->pixelformat;
>>                        break;
>>                }
>> -     }
>> -     /* Step 2: We can continue with this RAW format, or we can look
>> -      * for better: maybe sensor supports directly what we need.
>> -      */
>> -     direct_fmt = find_format_by_fourcc(isc, pixfmt->pixelformat);
>> -
>> -     /* Step 3: We have both. We decide given the module parameter which
>> -      * one to use.
>> -      */
>> -     if (direct_fmt && sd_fmt && sensor_preferred)
>> -             sd_fmt = direct_fmt;
>> -
>> -     /* Step 4: we do not have RAW but we have a direct format. Use it. */
>> -     if (direct_fmt && !sd_fmt)
>> -             sd_fmt = direct_fmt;
>> -
>> -     /* Step 5: if we are using a direct format, we need to package
>> -      * everything as 8 bit data and just dump it
>> -      */
>> -     if (sd_fmt == direct_fmt)
>> -             rlp_dma_direct_dump = true;
>> -
>> -     /* Step 6: We have no format. This can happen if the userspace
>> -      * requests some weird/invalid format.
>> -      * In this case, default to whatever we have
>> -      */
>> -     if (!sd_fmt && !direct_fmt) {
>> -             sd_fmt = isc->user_formats[isc->num_user_formats - 1];
>> -             v4l2_dbg(1, debug, &isc->v4l2_dev,
>> -                      "Sensor not supporting %.4s, using %.4s\n",
>> -                      (char *)&pixfmt->pixelformat, (char *)&sd_fmt->fourcc);
>> -     }
>> -
>> -     if (!sd_fmt) {
>> -             ret = -EINVAL;
>> -             goto isc_try_fmt_err;
>> -     }
>> -
>> -     /* Step 7: Print out what we decided for debugging */
>> -     v4l2_dbg(1, debug, &isc->v4l2_dev,
>> -              "Preferring to have sensor using format %.4s\n",
>> -              (char *)&sd_fmt->fourcc);
>>
>> -     /* Step 8: at this moment we decided which format the subdev will use */
>> -     isc->try_config.sd_format = sd_fmt;
>> +     isc_try_configure_rlp_dma(isc, false);
>>
>>        /* Limit to Atmel ISC hardware capabilities */
>> -     if (pixfmt->width > isc->max_width)
>> -             pixfmt->width = isc->max_width;
>> -     if (pixfmt->height > isc->max_height)
>> -             pixfmt->height = isc->max_height;
>> -
>> -     /*
>> -      * The mbus format is the one the subdev outputs.
>> -      * The pixels will be transferred in this format Sensor -> ISC
>> -      */
>> -     mbus_code = sd_fmt->mbus_code;
>> -
>> -     /*
>> -      * Validate formats. If the required format is not OK, default to raw.
>> -      */
>> -
>> -     isc->try_config.fourcc = pixfmt->pixelformat;
>> -
>> -     if (isc_try_validate_formats(isc)) {
>> -             pixfmt->pixelformat = isc->try_config.fourcc = sd_fmt->fourcc;
>> -             /* Re-try to validate the new format */
>> -             ret = isc_try_validate_formats(isc);
>> -             if (ret)
>> -                     goto isc_try_fmt_err;
>> -     }
>> -
>> -     ret = isc_try_configure_rlp_dma(isc, rlp_dma_direct_dump);
>> -     if (ret)
>> -             goto isc_try_fmt_err;
>> -
>> -     ret = isc_try_configure_pipeline(isc);
>> -     if (ret)
>> -             goto isc_try_fmt_err;
>> -
>> -     /* Obtain frame sizes if possible to have crop requirements ready */
>> -     isc_try_fse(isc, &pad_state);
>> -
>> -     v4l2_fill_mbus_format(&format.format, pixfmt, mbus_code);
>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, set_fmt,
>> -                            &pad_state, &format);
>> -     if (ret < 0)
>> -             goto isc_try_fmt_subdev_err;
>> -
>> -     v4l2_fill_pix_format(pixfmt, &format.format);
>> +     v4l_bound_align_image(&pixfmt->width, 16, isc->max_width, 0,
>> +                           &pixfmt->height, 16, isc->max_height, 0, 0);
>> +     /* If we did not find the requested format, we will fallback here */
>> +     pixfmt->pixelformat = isc->try_config.fourcc;
>> +     pixfmt->colorspace = V4L2_COLORSPACE_SRGB;
>> +     pixfmt->field = V4L2_FIELD_NONE;
>>
>> -     /* Limit to Atmel ISC hardware capabilities */
>> -     if (pixfmt->width > isc->max_width)
>> -             pixfmt->width = isc->max_width;
>> -     if (pixfmt->height > isc->max_height)
>> -             pixfmt->height = isc->max_height;
>>
>> -     pixfmt->field = V4L2_FIELD_NONE;
>>        pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
>>        pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
>>                             pixfmt->height;
>>
>> -     if (code)
>> -             *code = mbus_code;
>> +     isc->try_fmt = *f;
>>
>>        return 0;
>> +}
>>
>> -isc_try_fmt_err:
>> -     v4l2_err(&isc->v4l2_dev, "Could not find any possible format for a working pipeline\n");
>> -isc_try_fmt_subdev_err:
>> -     memset(&isc->try_config, 0, sizeof(isc->try_config));
>> +static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>> +{
>> +     isc_try_fmt(isc, f);
>>
>> -     return ret;
>> +     /* make the try configuration active */
>> +     isc->config = isc->try_config;
>> +     isc->fmt = isc->try_fmt;
>> +
>> +     v4l2_dbg(1, debug, &isc->v4l2_dev, "ISC set_fmt to %.4s @%dx%d\n",
>> +              (char *)&f->fmt.pix.pixelformat,
>> +              f->fmt.pix.width, f->fmt.pix.height);
>> +
>> +     return 0;
>>   }
>>
>> -static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>> +static int isc_validate(struct isc_device *isc)
>>   {
>> +     int ret;
>> +     int i;
>> +     struct isc_format *sd_fmt = NULL;
>> +     struct v4l2_pix_format *pixfmt = &isc->fmt.fmt.pix;
>>        struct v4l2_subdev_format format = {
>>                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>> +             .pad = isc->remote_pad,
>> +     };
>> +     struct v4l2_subdev_pad_config pad_cfg = {};
>> +     struct v4l2_subdev_state pad_state = {
>> +             .pads = &pad_cfg,
>>        };
>> -     u32 mbus_code = 0;
>> -     int ret;
>>
>> -     ret = isc_try_fmt(isc, f, &mbus_code);
>> +     /* Get current format from subdev */
>> +     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, get_fmt, NULL,
>> +                            &format);
>>        if (ret)
>>                return ret;
>>
>> -     v4l2_fill_mbus_format(&format.format, &f->fmt.pix, mbus_code);
>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad,
>> -                            set_fmt, NULL, &format);
>> -     if (ret < 0)
>> -             return ret;
>> +     /* Identify the subdev's format configuration */
>> +     for (i = 0; i < isc->formats_list_size; i++)
>> +             if (isc->formats_list[i].mbus_code == format.format.code) {
>> +                     sd_fmt = &isc->formats_list[i];
>> +                     break;
>> +             }
>> +
>> +     /* Check if the format is not supported */
>> +     if (!sd_fmt) {
>> +             v4l2_err(&isc->v4l2_dev,
>> +                      "Current subdevice is streaming a media bus code that is not supported 0x%x\n",
>> +                      format.format.code);
>> +             return -EPIPE;
>> +     }
>> +
>> +     /* At this moment we know which format the subdev will use */
>> +     isc->try_config.sd_format = sd_fmt;
>> +
>> +     /* If the sensor is not RAW, we can only do a direct dump */
>> +     if (!ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>> +             isc_try_configure_rlp_dma(isc, true);
>>
>>        /* Limit to Atmel ISC hardware capabilities */
>> -     if (f->fmt.pix.width > isc->max_width)
>> -             f->fmt.pix.width = isc->max_width;
>> -     if (f->fmt.pix.height > isc->max_height)
>> -             f->fmt.pix.height = isc->max_height;
>> +     v4l_bound_align_image(&format.format.width, 16, isc->max_width, 0,
>> +                           &format.format.height, 16, isc->max_height, 0, 0);
>>
>> -     isc->fmt = *f;
>> +     /* Check if the frame size is the same. Otherwise we may overflow */
>> +     if (pixfmt->height != format.format.height ||
>> +         pixfmt->width != format.format.width) {
>> +             v4l2_err(&isc->v4l2_dev,
>> +                      "ISC not configured with the proper frame size: %dx%d\n",
>> +                      format.format.width, format.format.height);
>> +             return -EPIPE;
>> +     }
>>
>> +     v4l2_dbg(1, debug, &isc->v4l2_dev,
>> +              "Identified subdev using format %.4s with %dx%d %d bpp\n",
>> +              (char *)&sd_fmt->fourcc, pixfmt->width, pixfmt->height,
>> +              isc->try_config.bpp);
>> +
>> +     /* Reset and restart AWB if the subdevice changed the format */
>>        if (isc->try_config.sd_format && isc->config.sd_format &&
>>            isc->try_config.sd_format != isc->config.sd_format) {
>>                isc->ctrls.hist_stat = HIST_INIT;
>>                isc_reset_awb_ctrls(isc);
>>                isc_update_v4l2_ctrls(isc);
>>        }
>> -     /* make the try configuration active */
>> +
>> +     /* Validate formats */
>> +     ret = isc_try_validate_formats(isc);
>> +     if (ret)
>> +             return ret;
>> +
>> +     /* Obtain frame sizes if possible to have crop requirements ready */
>> +     isc_try_fse(isc, &pad_state);
>> +
>> +     /* Configure ISC pipeline for the config */
>> +     ret = isc_try_configure_pipeline(isc);
>> +     if (ret)
>> +             return ret;
>> +
>>        isc->config = isc->try_config;
>>
>>        v4l2_dbg(1, debug, &isc->v4l2_dev, "New ISC configuration in place\n");
>> @@ -1043,7 +1036,7 @@ static int isc_try_fmt_vid_cap(struct file *file, void *priv,
>>   {
>>        struct isc_device *isc = video_drvdata(file);
>>
>> -     return isc_try_fmt(isc, f, NULL);
>> +     return isc_try_fmt(isc, f);
>>   }
>>
>>   static int isc_enum_input(struct file *file, void *priv,
>> @@ -1098,10 +1091,6 @@ static int isc_enum_framesizes(struct file *file, void *fh,
>>        if (fsize->index)
>>                return -EINVAL;
>>
>> -     for (i = 0; i < isc->num_user_formats; i++)
>> -             if (isc->user_formats[i]->fourcc == fsize->pixel_format)
>> -                     ret = 0;
>> -
>>        for (i = 0; i < isc->controller_formats_size; i++)
>>                if (isc->controller_formats[i].fourcc == fsize->pixel_format)
>>                        ret = 0;
>> @@ -1782,52 +1771,6 @@ struct isc_format *isc_find_format_by_code(struct isc_device *isc,
>>   }
>>   EXPORT_SYMBOL_GPL(isc_find_format_by_code);
>>
>> -static int isc_formats_init(struct isc_device *isc)
>> -{
>> -     struct isc_format *fmt;
>> -     struct v4l2_subdev *subdev = isc->current_subdev->sd;
>> -     unsigned int num_fmts, i, j;
>> -     u32 list_size = isc->formats_list_size;
>> -     struct v4l2_subdev_mbus_code_enum mbus_code = {
>> -             .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>> -     };
>> -
>> -     num_fmts = 0;
>> -     while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
>> -            NULL, &mbus_code)) {
>> -             mbus_code.index++;
>> -
>> -             fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
>> -             if (!fmt) {
>> -                     v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
>> -                               mbus_code.code);
>> -                     continue;
>> -             }
>> -
>> -             fmt->sd_support = true;
>> -             num_fmts++;
>> -     }
>> -
>> -     if (!num_fmts)
>> -             return -ENXIO;
>> -
>> -     isc->num_user_formats = num_fmts;
>> -     isc->user_formats = devm_kcalloc(isc->dev,
>> -                                      num_fmts, sizeof(*isc->user_formats),
>> -                                      GFP_KERNEL);
>> -     if (!isc->user_formats)
>> -             return -ENOMEM;
>> -
>> -     fmt = &isc->formats_list[0];
>> -     for (i = 0, j = 0; i < list_size; i++) {
>> -             if (fmt->sd_support)
>> -                     isc->user_formats[j++] = fmt;
>> -             fmt++;
>> -     }
>> -
>> -     return 0;
>> -}
>> -
>>   static int isc_set_default_fmt(struct isc_device *isc)
>>   {
>>        struct v4l2_format f = {
>> @@ -1836,12 +1779,12 @@ static int isc_set_default_fmt(struct isc_device *isc)
>>                        .width          = VGA_WIDTH,
>>                        .height         = VGA_HEIGHT,
>>                        .field          = V4L2_FIELD_NONE,
>> -                     .pixelformat    = isc->user_formats[0]->fourcc,
>> +                     .pixelformat    = isc->controller_formats[0].fourcc,
>>                },
>>        };
>>        int ret;
>>
>> -     ret = isc_try_fmt(isc, &f, NULL);
>> +     ret = isc_try_fmt(isc, &f);
>>        if (ret)
>>                return ret;
>>
>> @@ -1896,13 +1839,6 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
>>        spin_lock_init(&isc->dma_queue_lock);
>>        spin_lock_init(&isc->awb_lock);
>>
>> -     ret = isc_formats_init(isc);
>> -     if (ret < 0) {
>> -             v4l2_err(&isc->v4l2_dev,
>> -                      "Init format failed: %d\n", ret);
>> -             goto isc_async_complete_err;
>> -     }
>> -
>>        ret = isc_set_default_fmt(isc);
>>        if (ret) {
>>                v4l2_err(&isc->v4l2_dev, "Could not set default format\n");
>> @@ -2016,6 +1952,24 @@ int isc_pipeline_init(struct isc_device *isc)
>>   }
>>   EXPORT_SYMBOL_GPL(isc_pipeline_init);
>>
>> +static int isc_link_validate(struct media_link *link)
>> +{
>> +     struct video_device *vdev =
>> +             media_entity_to_video_device(link->sink->entity);
>> +     struct isc_device *isc = video_get_drvdata(vdev);
>> +     int ret;
>> +
>> +     ret = v4l2_subdev_link_validate(link);
>> +     if (ret)
>> +             return ret;
>> +
>> +     return isc_validate(isc);
>> +}
>> +
>> +static const struct media_entity_operations isc_entity_operations = {
>> +     .link_validate = isc_link_validate,
>> +};
>> +
>>   int isc_mc_init(struct isc_device *isc, u32 ver)
>>   {
>>        const struct of_device_id *match;
>> @@ -2023,6 +1977,8 @@ int isc_mc_init(struct isc_device *isc, u32 ver)
>>
>>        isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
>>        isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
>> +     isc->video_dev.entity.ops = &isc_entity_operations;
>> +
>>        isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>
>>        ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
>> diff --git a/drivers/media/platform/atmel/atmel-isc-scaler.c b/drivers/media/platform/atmel/atmel-isc-scaler.c
>> index a1ca4633787c..2b0621297dfe 100644
>> --- a/drivers/media/platform/atmel/atmel-isc-scaler.c
>> +++ b/drivers/media/platform/atmel/atmel-isc-scaler.c
>> @@ -173,6 +173,10 @@ static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
>>        .init_cfg = isc_scaler_init_cfg,
>>   };
>>
>> +static const struct media_entity_operations isc_scaler_entity_ops = {
>> +     .link_validate = v4l2_subdev_link_validate,
>> +};
>> +
>>   static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
>>        .pad = &isc_scaler_pad_ops,
>>   };
>> @@ -190,6 +194,7 @@ int isc_scaler_init(struct isc_device *isc)
>>
>>        isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>>        isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
>> +     isc->scaler_sd.entity.ops = &isc_scaler_entity_ops;
>>        isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>        isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
>>
>> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
>> index f98f25a55e73..5b0100c8c245 100644
>> --- a/drivers/media/platform/atmel/atmel-isc.h
>> +++ b/drivers/media/platform/atmel/atmel-isc.h
>> @@ -63,15 +63,16 @@ struct isc_subdev_entity {
>>    * @cfa_baycfg:              If this format is RAW BAYER, indicate the type of bayer.
>>                        this is either BGBG, RGRG, etc.
>>    * @pfe_cfg0_bps:    Number of hardware data lines connected to the ISC
>> + * @raw:             If the format is raw bayer.
>>    */
>>
>>   struct isc_format {
>>        u32     fourcc;
>>        u32     mbus_code;
>>        u32     cfa_baycfg;
>> -
>> -     bool    sd_support;
>>        u32     pfe_cfg0_bps;
>> +
>> +     bool    raw;
>>   };
>>
>>   /* Pipeline bitmap */
>> @@ -216,8 +217,7 @@ enum isc_scaler_pads {
>>    * @comp:            completion reference that signals frame completion
>>    *
>>    * @fmt:             current v42l format
>> - * @user_formats:    list of formats that are supported and agreed with sd
>> - * @num_user_formats:        how many formats are in user_formats
>> + * @try_fmt:         current v4l2 try format
>>    *
>>    * @config:          current ISC format configuration
>>    * @try_config:              the current ISC try format , not yet activated
>> @@ -272,6 +272,7 @@ enum isc_scaler_pads {
>>    * @formats_list_size:       size of formats_list array
>>    * @pads:            media controller pads for isc video entity
>>    * @mdev:            media device that is registered by the isc
>> + * @mpipe:           media device pipeline used by the isc
>>    * @remote_pad:              remote pad on the connected subdevice
>>    * @scaler_sd:               subdevice for the scaler that isc registers
>>    * @scaler_pads:     media controller pads for the scaler subdevice
>> @@ -298,8 +299,7 @@ struct isc_device {
>>        struct completion       comp;
>>
>>        struct v4l2_format      fmt;
>> -     struct isc_format       **user_formats;
>> -     unsigned int            num_user_formats;
>> +     struct v4l2_format      try_fmt;
>>
>>        struct fmt_config       config;
>>        struct fmt_config       try_config;
>> @@ -369,6 +369,7 @@ struct isc_device {
>>        struct {
>>                struct media_pad                pads[ISC_PADS_NUM];
>>                struct media_device             mdev;
>> +             struct media_pipeline           mpipe;
>>
>>                u32                             remote_pad;
>>        };
>> diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>> index d96ee3373889..2a651e237193 100644
>> --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>> +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>> @@ -80,20 +80,40 @@ static const struct isc_format sama5d2_controller_formats[] = {
>>                .fourcc         = V4L2_PIX_FMT_Y10,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
>> +             .raw            = true,
>> +     }, {
>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
>> +             .raw            = true,
>> +     }, {
>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
>> +             .raw            = true,
>> +     }, {
>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
>> +             .raw            = true,
>> +     }, {
>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
>> +             .raw            = true,
>>        },
>>   };
>>
>> diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>> index e07ae188c15f..a0d60cfdba7b 100644
>> --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>> +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>> @@ -89,20 +89,40 @@ static const struct isc_format sama7g5_controller_formats[] = {
>>                .fourcc         = V4L2_PIX_FMT_Y16,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
>> +             .raw            = true,
>>        }, {
>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
>> +             .raw            = true,
>> +     }, {
>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
>> +             .raw            = true,
>> +     }, {
>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
>> +             .raw            = true,
>> +     }, {
>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
>> +             .raw            = true,
>> +     }, {
>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
>> +             .raw            = true,
>>        },
>>   };
>>
>

On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
> On 4/29/22 11:17 AM, Hans Verkuil wrote:
>> On 10/03/2022 10:51, Eugen Hristev wrote:
>>> As a top MC video driver, the atmel-isc should not propagate the format to the
>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
>>> configured with a compatible format.
>>> Removed the whole format finding logic, and reworked the format verification
>>> at start_streaming time, such that the ISC will return an error if the subdevice
>>> is not properly configured. To achieve this, media_pipeline_start
>>> is called and a link_validate callback is created to check the formats.
>>> With this being done, the module parameter 'sensor_preferred' makes no sense
>>> anymore. The ISC should not decide which format the sensor is using. The
>>> ISC should only cope with the situation and inform userspace if the streaming
>>> is possible in the current configuration.
>>> The redesign of the format propagation has also risen the question of the
>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
>>> should only return the formats that are supported for this mbus_code.
>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
>>> With this rework, the dynamic list of user formats is removed. It makes no
>>> more sense to identify at complete time which formats the sensor could emit,
>>> and add those into a separate dynamic list.
>>> The ISC will start with a simple preconfigured default format, and at
>>> link validate time, decide whether it can use the format that is configured
>>> on the sink or not.
>>>
>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>>> ---
>>> Changes in v9:
>>> - isc_link_validate now static
>>>
>>> Changes in v7:
>>> - minor typos as suggested by Jacopo
>>> - small changes, reduce some indentation, modified an index, as suggested by
>>> Jacopo
>>>
>>> Changes in v6:
>>> - reworked a bit enum_fmt as suggested by Jacopo
>>>
>>> Changes in v5:
>>> - removed user_formats dynamic list as it is now pointless
>>> - greatly simplified the enum_fmt function
>>> - removed some init code that was useless now
>>>
>>> Changes in v4:
>>> - moved validation code into link_validate and used media_pipeline_start
>>> - merged this patch with the enum_fmt patch which was previously in v3 of
>>> the series
>>>
>>> Changes in v3:
>>> - clamp to maximum resolution once the frame size from the subdev is found
>>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>>>   5 files changed, 236 insertions(+), 234 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>>> index ee1dda6707a0..fe2c0af58060 100644
>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>>> @@ -36,11 +36,6 @@ static unsigned int debug;
>>>   module_param(debug, int, 0644);
>>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
>>>
>>> -static unsigned int sensor_preferred = 1;
>>> -module_param(sensor_preferred, uint, 0644);
>>> -MODULE_PARM_DESC(sensor_preferred,
>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>>> -
>>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
>>>        (((mbus_code) & 0xf000) == 0x3000)
>>>
>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>        unsigned long flags;
>>>        int ret;
>>>
>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
>>
>> The pipeline validation is done in start_streaming, but I don't think that
>> is the best place: if STREAMON is called before buffers are queued, then
>> an invalid pipeline isn't discovered until enough buffers are queued to
>> kick off start_streaming.
>>
>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
>>
>> I think that is the correct time to do this.
> 
> Hello Hans,
> 
> Initially (v2, v3) I had this in streamon(). The problem that I faced at 
> that time was that streamoff was never called, so I could not call 
> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming 
> (see change log for v4) , and I did not face any more problems.

It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
isn't called), exynos4-is does the same, but it also checks the streaming state in
the release() fop callback, so that would fix this problem. And vimc does this
in stop_streaming.

I'm in favor of fixing this in vb2, that framework knows exactly when this needs
to be called.

I'd like to know what others think.

Regards,

	Hans

> 
> Eugen
> 
>>
>> Laurent, Jacopo, do you agree with that?
>>
>> I notice that quite a few other drivers do this in start_streaming as well,
>> but I think it just weird that a QBUF can return EPIPE while STREAMON might
>> succeed.
>>
>> Perhaps we need an optional vb2 validate() callback that is called by
>> vb2_core_streamon() to validate the pipeline before streaming. That makes
>> it easier to implement these checks rather than having to implement your
>> own streamon ioctl.
>>
>> Regards,
>>
>>          Hans
>>
>>> +     if (ret)
>>> +             goto err_pipeline_start;
>>> +
>>>        /* Enable stream on the sub device */
>>>        ret = v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 1);
>>>        if (ret && ret != -ENOIOCTLCMD) {
>>> @@ -385,6 +384,9 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>        v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
>>>
>>>   err_start_stream:
>>> +     media_pipeline_stop(&isc->video_dev.entity);
>>> +
>>> +err_pipeline_start:
>>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
>>>        list_for_each_entry(buf, &isc->dma_queue, list)
>>>                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
>>> @@ -423,6 +425,9 @@ static void isc_stop_streaming(struct vb2_queue *vq)
>>>        if (ret && ret != -ENOIOCTLCMD)
>>>                v4l2_err(&isc->v4l2_dev, "stream off failed in subdev\n");
>>>
>>> +     /* Stop media pipeline */
>>> +     media_pipeline_stop(&isc->video_dev.entity);
>>> +
>>>        /* Release all active buffers */
>>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
>>>        if (unlikely(isc->cur_frm)) {
>>> @@ -453,22 +458,6 @@ static void isc_buffer_queue(struct vb2_buffer *vb)
>>>        spin_unlock_irqrestore(&isc->dma_queue_lock, flags);
>>>   }
>>>
>>> -static struct isc_format *find_format_by_fourcc(struct isc_device *isc,
>>> -                                              unsigned int fourcc)
>>> -{
>>> -     unsigned int num_formats = isc->num_user_formats;
>>> -     struct isc_format *fmt;
>>> -     unsigned int i;
>>> -
>>> -     for (i = 0; i < num_formats; i++) {
>>> -             fmt = isc->user_formats[i];
>>> -             if (fmt->fourcc == fourcc)
>>> -                     return fmt;
>>> -     }
>>> -
>>> -     return NULL;
>>> -}
>>> -
>>>   static const struct vb2_ops isc_vb2_ops = {
>>>        .queue_setup            = isc_queue_setup,
>>>        .wait_prepare           = vb2_ops_wait_prepare,
>>> @@ -497,23 +486,57 @@ static int isc_enum_fmt_vid_cap(struct file *file, void *priv,
>>>   {
>>>        struct isc_device *isc = video_drvdata(file);
>>>        u32 index = f->index;
>>> -     u32 i, supported_index;
>>> +     u32 i, supported_index = 0;
>>> +     struct isc_format *fmt;
>>> +
>>> +     /*
>>> +      * If we are not asked a specific mbus_code, we have to report all
>>> +      * the formats that we can output.
>>> +      */
>>> +     if (!f->mbus_code) {
>>> +             if (index >= isc->controller_formats_size)
>>> +                     return -EINVAL;
>>>
>>> -     if (index < isc->controller_formats_size) {
>>>                f->pixelformat = isc->controller_formats[index].fourcc;
>>> +
>>> +             return 0;
>>> +     }
>>> +
>>> +     /*
>>> +      * If a specific mbus_code is requested, check if we support
>>> +      * this mbus_code as input for the ISC.
>>> +      * If it's supported, then we report the corresponding pixelformat
>>> +      * as first possible option for the ISC.
>>> +      * E.g. mbus MEDIA_BUS_FMT_YUYV8_2X8 and report
>>> +      * 'YUYV' (YUYV 4:2:2)
>>> +      */
>>> +     fmt = isc_find_format_by_code(isc, f->mbus_code, &i);
>>> +     if (!fmt)
>>> +             return -EINVAL;
>>> +
>>> +     if (!index) {
>>> +             f->pixelformat = fmt->fourcc;
>>> +
>>>                return 0;
>>>        }
>>>
>>> -     index -= isc->controller_formats_size;
>>> +     supported_index++;
>>>
>>> -     supported_index = 0;
>>> +     /* If the index is not raw, we don't have anymore formats to report */
>>> +     if (!ISC_IS_FORMAT_RAW(f->mbus_code))
>>> +             return -EINVAL;
>>>
>>> -     for (i = 0; i < isc->formats_list_size; i++) {
>>> -             if (!ISC_IS_FORMAT_RAW(isc->formats_list[i].mbus_code) ||
>>> -                 !isc->formats_list[i].sd_support)
>>> +     /*
>>> +      * We are asked for a specific mbus code, which is raw.
>>> +      * We have to search through the formats we can convert to.
>>> +      * We have to skip the raw formats, we cannot convert to raw.
>>> +      * E.g. 'AR12' (16-bit ARGB 4-4-4-4), 'AR15' (16-bit ARGB 1-5-5-5), etc.
>>> +      */
>>> +     for (i = 0; i < isc->controller_formats_size; i++) {
>>> +             if (isc->controller_formats[i].raw)
>>>                        continue;
>>> -             if (supported_index == index) {
>>> -                     f->pixelformat = isc->formats_list[i].fourcc;
>>> +             if (index == supported_index) {
>>> +                     f->pixelformat = isc->controller_formats[i].fourcc;
>>>                        return 0;
>>>                }
>>>                supported_index++;
>>> @@ -584,20 +607,30 @@ static int isc_try_validate_formats(struct isc_device *isc)
>>>                break;
>>>        default:
>>>        /* any other different formats are not supported */
>>> +             v4l2_err(&isc->v4l2_dev, "Requested unsupported format.\n");
>>>                ret = -EINVAL;
>>>        }
>>>        v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>                 "Format validation, requested rgb=%u, yuv=%u, grey=%u, bayer=%u\n",
>>>                 rgb, yuv, grey, bayer);
>>>
>>> -     /* we cannot output RAW if we do not receive RAW */
>>> -     if ((bayer) && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>>> +     if (bayer &&
>>> +         !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code)) {
>>> +             v4l2_err(&isc->v4l2_dev, "Cannot output RAW if we do not receive RAW.\n");
>>>                return -EINVAL;
>>> +     }
>>>
>>> -     /* we cannot output GREY if we do not receive RAW/GREY */
>>>        if (grey && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code) &&
>>> -         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code))
>>> +         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>>> +             v4l2_err(&isc->v4l2_dev, "Cannot output GREY if we do not receive RAW/GREY.\n");
>>>                return -EINVAL;
>>> +     }
>>> +
>>> +     if ((rgb || bayer || yuv) &&
>>> +         ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>>> +             v4l2_err(&isc->v4l2_dev, "Cannot convert GREY to another format.\n");
>>> +             return -EINVAL;
>>> +     }
>>>
>>>        return ret;
>>>   }
>>> @@ -825,7 +858,7 @@ static void isc_try_fse(struct isc_device *isc,
>>>         * If we do not know yet which format the subdev is using, we cannot
>>>         * do anything.
>>>         */
>>> -     if (!isc->try_config.sd_format)
>>> +     if (!isc->config.sd_format)
>>>                return;
>>>
>>>        fse.code = isc->try_config.sd_format->mbus_code;
>>> @@ -846,180 +879,140 @@ static void isc_try_fse(struct isc_device *isc,
>>>        }
>>>   }
>>>
>>> -static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
>>> -                     u32 *code)
>>> +static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f)
>>>   {
>>> -     int i;
>>> -     struct isc_format *sd_fmt = NULL, *direct_fmt = NULL;
>>>        struct v4l2_pix_format *pixfmt = &f->fmt.pix;
>>> -     struct v4l2_subdev_pad_config pad_cfg = {};
>>> -     struct v4l2_subdev_state pad_state = {
>>> -             .pads = &pad_cfg
>>> -             };
>>> -     struct v4l2_subdev_format format = {
>>> -             .which = V4L2_SUBDEV_FORMAT_TRY,
>>> -     };
>>> -     u32 mbus_code;
>>> -     int ret;
>>> -     bool rlp_dma_direct_dump = false;
>>> +     unsigned int i;
>>>
>>>        if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>>>                return -EINVAL;
>>>
>>> -     /* Step 1: find a RAW format that is supported */
>>> -     for (i = 0; i < isc->num_user_formats; i++) {
>>> -             if (ISC_IS_FORMAT_RAW(isc->user_formats[i]->mbus_code)) {
>>> -                     sd_fmt = isc->user_formats[i];
>>> +     isc->try_config.fourcc = isc->controller_formats[0].fourcc;
>>> +
>>> +     /* find if the format requested is supported */
>>> +     for (i = 0; i < isc->controller_formats_size; i++)
>>> +             if (isc->controller_formats[i].fourcc == pixfmt->pixelformat) {
>>> +                     isc->try_config.fourcc = pixfmt->pixelformat;
>>>                        break;
>>>                }
>>> -     }
>>> -     /* Step 2: We can continue with this RAW format, or we can look
>>> -      * for better: maybe sensor supports directly what we need.
>>> -      */
>>> -     direct_fmt = find_format_by_fourcc(isc, pixfmt->pixelformat);
>>> -
>>> -     /* Step 3: We have both. We decide given the module parameter which
>>> -      * one to use.
>>> -      */
>>> -     if (direct_fmt && sd_fmt && sensor_preferred)
>>> -             sd_fmt = direct_fmt;
>>> -
>>> -     /* Step 4: we do not have RAW but we have a direct format. Use it. */
>>> -     if (direct_fmt && !sd_fmt)
>>> -             sd_fmt = direct_fmt;
>>> -
>>> -     /* Step 5: if we are using a direct format, we need to package
>>> -      * everything as 8 bit data and just dump it
>>> -      */
>>> -     if (sd_fmt == direct_fmt)
>>> -             rlp_dma_direct_dump = true;
>>> -
>>> -     /* Step 6: We have no format. This can happen if the userspace
>>> -      * requests some weird/invalid format.
>>> -      * In this case, default to whatever we have
>>> -      */
>>> -     if (!sd_fmt && !direct_fmt) {
>>> -             sd_fmt = isc->user_formats[isc->num_user_formats - 1];
>>> -             v4l2_dbg(1, debug, &isc->v4l2_dev,
>>> -                      "Sensor not supporting %.4s, using %.4s\n",
>>> -                      (char *)&pixfmt->pixelformat, (char *)&sd_fmt->fourcc);
>>> -     }
>>> -
>>> -     if (!sd_fmt) {
>>> -             ret = -EINVAL;
>>> -             goto isc_try_fmt_err;
>>> -     }
>>> -
>>> -     /* Step 7: Print out what we decided for debugging */
>>> -     v4l2_dbg(1, debug, &isc->v4l2_dev,
>>> -              "Preferring to have sensor using format %.4s\n",
>>> -              (char *)&sd_fmt->fourcc);
>>>
>>> -     /* Step 8: at this moment we decided which format the subdev will use */
>>> -     isc->try_config.sd_format = sd_fmt;
>>> +     isc_try_configure_rlp_dma(isc, false);
>>>
>>>        /* Limit to Atmel ISC hardware capabilities */
>>> -     if (pixfmt->width > isc->max_width)
>>> -             pixfmt->width = isc->max_width;
>>> -     if (pixfmt->height > isc->max_height)
>>> -             pixfmt->height = isc->max_height;
>>> -
>>> -     /*
>>> -      * The mbus format is the one the subdev outputs.
>>> -      * The pixels will be transferred in this format Sensor -> ISC
>>> -      */
>>> -     mbus_code = sd_fmt->mbus_code;
>>> -
>>> -     /*
>>> -      * Validate formats. If the required format is not OK, default to raw.
>>> -      */
>>> -
>>> -     isc->try_config.fourcc = pixfmt->pixelformat;
>>> -
>>> -     if (isc_try_validate_formats(isc)) {
>>> -             pixfmt->pixelformat = isc->try_config.fourcc = sd_fmt->fourcc;
>>> -             /* Re-try to validate the new format */
>>> -             ret = isc_try_validate_formats(isc);
>>> -             if (ret)
>>> -                     goto isc_try_fmt_err;
>>> -     }
>>> -
>>> -     ret = isc_try_configure_rlp_dma(isc, rlp_dma_direct_dump);
>>> -     if (ret)
>>> -             goto isc_try_fmt_err;
>>> -
>>> -     ret = isc_try_configure_pipeline(isc);
>>> -     if (ret)
>>> -             goto isc_try_fmt_err;
>>> -
>>> -     /* Obtain frame sizes if possible to have crop requirements ready */
>>> -     isc_try_fse(isc, &pad_state);
>>> -
>>> -     v4l2_fill_mbus_format(&format.format, pixfmt, mbus_code);
>>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, set_fmt,
>>> -                            &pad_state, &format);
>>> -     if (ret < 0)
>>> -             goto isc_try_fmt_subdev_err;
>>> -
>>> -     v4l2_fill_pix_format(pixfmt, &format.format);
>>> +     v4l_bound_align_image(&pixfmt->width, 16, isc->max_width, 0,
>>> +                           &pixfmt->height, 16, isc->max_height, 0, 0);
>>> +     /* If we did not find the requested format, we will fallback here */
>>> +     pixfmt->pixelformat = isc->try_config.fourcc;
>>> +     pixfmt->colorspace = V4L2_COLORSPACE_SRGB;
>>> +     pixfmt->field = V4L2_FIELD_NONE;
>>>
>>> -     /* Limit to Atmel ISC hardware capabilities */
>>> -     if (pixfmt->width > isc->max_width)
>>> -             pixfmt->width = isc->max_width;
>>> -     if (pixfmt->height > isc->max_height)
>>> -             pixfmt->height = isc->max_height;
>>>
>>> -     pixfmt->field = V4L2_FIELD_NONE;
>>>        pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
>>>        pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
>>>                             pixfmt->height;
>>>
>>> -     if (code)
>>> -             *code = mbus_code;
>>> +     isc->try_fmt = *f;
>>>
>>>        return 0;
>>> +}
>>>
>>> -isc_try_fmt_err:
>>> -     v4l2_err(&isc->v4l2_dev, "Could not find any possible format for a working pipeline\n");
>>> -isc_try_fmt_subdev_err:
>>> -     memset(&isc->try_config, 0, sizeof(isc->try_config));
>>> +static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>>> +{
>>> +     isc_try_fmt(isc, f);
>>>
>>> -     return ret;
>>> +     /* make the try configuration active */
>>> +     isc->config = isc->try_config;
>>> +     isc->fmt = isc->try_fmt;
>>> +
>>> +     v4l2_dbg(1, debug, &isc->v4l2_dev, "ISC set_fmt to %.4s @%dx%d\n",
>>> +              (char *)&f->fmt.pix.pixelformat,
>>> +              f->fmt.pix.width, f->fmt.pix.height);
>>> +
>>> +     return 0;
>>>   }
>>>
>>> -static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>>> +static int isc_validate(struct isc_device *isc)
>>>   {
>>> +     int ret;
>>> +     int i;
>>> +     struct isc_format *sd_fmt = NULL;
>>> +     struct v4l2_pix_format *pixfmt = &isc->fmt.fmt.pix;
>>>        struct v4l2_subdev_format format = {
>>>                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>>> +             .pad = isc->remote_pad,
>>> +     };
>>> +     struct v4l2_subdev_pad_config pad_cfg = {};
>>> +     struct v4l2_subdev_state pad_state = {
>>> +             .pads = &pad_cfg,
>>>        };
>>> -     u32 mbus_code = 0;
>>> -     int ret;
>>>
>>> -     ret = isc_try_fmt(isc, f, &mbus_code);
>>> +     /* Get current format from subdev */
>>> +     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, get_fmt, NULL,
>>> +                            &format);
>>>        if (ret)
>>>                return ret;
>>>
>>> -     v4l2_fill_mbus_format(&format.format, &f->fmt.pix, mbus_code);
>>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad,
>>> -                            set_fmt, NULL, &format);
>>> -     if (ret < 0)
>>> -             return ret;
>>> +     /* Identify the subdev's format configuration */
>>> +     for (i = 0; i < isc->formats_list_size; i++)
>>> +             if (isc->formats_list[i].mbus_code == format.format.code) {
>>> +                     sd_fmt = &isc->formats_list[i];
>>> +                     break;
>>> +             }
>>> +
>>> +     /* Check if the format is not supported */
>>> +     if (!sd_fmt) {
>>> +             v4l2_err(&isc->v4l2_dev,
>>> +                      "Current subdevice is streaming a media bus code that is not supported 0x%x\n",
>>> +                      format.format.code);
>>> +             return -EPIPE;
>>> +     }
>>> +
>>> +     /* At this moment we know which format the subdev will use */
>>> +     isc->try_config.sd_format = sd_fmt;
>>> +
>>> +     /* If the sensor is not RAW, we can only do a direct dump */
>>> +     if (!ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>>> +             isc_try_configure_rlp_dma(isc, true);
>>>
>>>        /* Limit to Atmel ISC hardware capabilities */
>>> -     if (f->fmt.pix.width > isc->max_width)
>>> -             f->fmt.pix.width = isc->max_width;
>>> -     if (f->fmt.pix.height > isc->max_height)
>>> -             f->fmt.pix.height = isc->max_height;
>>> +     v4l_bound_align_image(&format.format.width, 16, isc->max_width, 0,
>>> +                           &format.format.height, 16, isc->max_height, 0, 0);
>>>
>>> -     isc->fmt = *f;
>>> +     /* Check if the frame size is the same. Otherwise we may overflow */
>>> +     if (pixfmt->height != format.format.height ||
>>> +         pixfmt->width != format.format.width) {
>>> +             v4l2_err(&isc->v4l2_dev,
>>> +                      "ISC not configured with the proper frame size: %dx%d\n",
>>> +                      format.format.width, format.format.height);
>>> +             return -EPIPE;
>>> +     }
>>>
>>> +     v4l2_dbg(1, debug, &isc->v4l2_dev,
>>> +              "Identified subdev using format %.4s with %dx%d %d bpp\n",
>>> +              (char *)&sd_fmt->fourcc, pixfmt->width, pixfmt->height,
>>> +              isc->try_config.bpp);
>>> +
>>> +     /* Reset and restart AWB if the subdevice changed the format */
>>>        if (isc->try_config.sd_format && isc->config.sd_format &&
>>>            isc->try_config.sd_format != isc->config.sd_format) {
>>>                isc->ctrls.hist_stat = HIST_INIT;
>>>                isc_reset_awb_ctrls(isc);
>>>                isc_update_v4l2_ctrls(isc);
>>>        }
>>> -     /* make the try configuration active */
>>> +
>>> +     /* Validate formats */
>>> +     ret = isc_try_validate_formats(isc);
>>> +     if (ret)
>>> +             return ret;
>>> +
>>> +     /* Obtain frame sizes if possible to have crop requirements ready */
>>> +     isc_try_fse(isc, &pad_state);
>>> +
>>> +     /* Configure ISC pipeline for the config */
>>> +     ret = isc_try_configure_pipeline(isc);
>>> +     if (ret)
>>> +             return ret;
>>> +
>>>        isc->config = isc->try_config;
>>>
>>>        v4l2_dbg(1, debug, &isc->v4l2_dev, "New ISC configuration in place\n");
>>> @@ -1043,7 +1036,7 @@ static int isc_try_fmt_vid_cap(struct file *file, void *priv,
>>>   {
>>>        struct isc_device *isc = video_drvdata(file);
>>>
>>> -     return isc_try_fmt(isc, f, NULL);
>>> +     return isc_try_fmt(isc, f);
>>>   }
>>>
>>>   static int isc_enum_input(struct file *file, void *priv,
>>> @@ -1098,10 +1091,6 @@ static int isc_enum_framesizes(struct file *file, void *fh,
>>>        if (fsize->index)
>>>                return -EINVAL;
>>>
>>> -     for (i = 0; i < isc->num_user_formats; i++)
>>> -             if (isc->user_formats[i]->fourcc == fsize->pixel_format)
>>> -                     ret = 0;
>>> -
>>>        for (i = 0; i < isc->controller_formats_size; i++)
>>>                if (isc->controller_formats[i].fourcc == fsize->pixel_format)
>>>                        ret = 0;
>>> @@ -1782,52 +1771,6 @@ struct isc_format *isc_find_format_by_code(struct isc_device *isc,
>>>   }
>>>   EXPORT_SYMBOL_GPL(isc_find_format_by_code);
>>>
>>> -static int isc_formats_init(struct isc_device *isc)
>>> -{
>>> -     struct isc_format *fmt;
>>> -     struct v4l2_subdev *subdev = isc->current_subdev->sd;
>>> -     unsigned int num_fmts, i, j;
>>> -     u32 list_size = isc->formats_list_size;
>>> -     struct v4l2_subdev_mbus_code_enum mbus_code = {
>>> -             .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>>> -     };
>>> -
>>> -     num_fmts = 0;
>>> -     while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
>>> -            NULL, &mbus_code)) {
>>> -             mbus_code.index++;
>>> -
>>> -             fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
>>> -             if (!fmt) {
>>> -                     v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
>>> -                               mbus_code.code);
>>> -                     continue;
>>> -             }
>>> -
>>> -             fmt->sd_support = true;
>>> -             num_fmts++;
>>> -     }
>>> -
>>> -     if (!num_fmts)
>>> -             return -ENXIO;
>>> -
>>> -     isc->num_user_formats = num_fmts;
>>> -     isc->user_formats = devm_kcalloc(isc->dev,
>>> -                                      num_fmts, sizeof(*isc->user_formats),
>>> -                                      GFP_KERNEL);
>>> -     if (!isc->user_formats)
>>> -             return -ENOMEM;
>>> -
>>> -     fmt = &isc->formats_list[0];
>>> -     for (i = 0, j = 0; i < list_size; i++) {
>>> -             if (fmt->sd_support)
>>> -                     isc->user_formats[j++] = fmt;
>>> -             fmt++;
>>> -     }
>>> -
>>> -     return 0;
>>> -}
>>> -
>>>   static int isc_set_default_fmt(struct isc_device *isc)
>>>   {
>>>        struct v4l2_format f = {
>>> @@ -1836,12 +1779,12 @@ static int isc_set_default_fmt(struct isc_device *isc)
>>>                        .width          = VGA_WIDTH,
>>>                        .height         = VGA_HEIGHT,
>>>                        .field          = V4L2_FIELD_NONE,
>>> -                     .pixelformat    = isc->user_formats[0]->fourcc,
>>> +                     .pixelformat    = isc->controller_formats[0].fourcc,
>>>                },
>>>        };
>>>        int ret;
>>>
>>> -     ret = isc_try_fmt(isc, &f, NULL);
>>> +     ret = isc_try_fmt(isc, &f);
>>>        if (ret)
>>>                return ret;
>>>
>>> @@ -1896,13 +1839,6 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
>>>        spin_lock_init(&isc->dma_queue_lock);
>>>        spin_lock_init(&isc->awb_lock);
>>>
>>> -     ret = isc_formats_init(isc);
>>> -     if (ret < 0) {
>>> -             v4l2_err(&isc->v4l2_dev,
>>> -                      "Init format failed: %d\n", ret);
>>> -             goto isc_async_complete_err;
>>> -     }
>>> -
>>>        ret = isc_set_default_fmt(isc);
>>>        if (ret) {
>>>                v4l2_err(&isc->v4l2_dev, "Could not set default format\n");
>>> @@ -2016,6 +1952,24 @@ int isc_pipeline_init(struct isc_device *isc)
>>>   }
>>>   EXPORT_SYMBOL_GPL(isc_pipeline_init);
>>>
>>> +static int isc_link_validate(struct media_link *link)
>>> +{
>>> +     struct video_device *vdev =
>>> +             media_entity_to_video_device(link->sink->entity);
>>> +     struct isc_device *isc = video_get_drvdata(vdev);
>>> +     int ret;
>>> +
>>> +     ret = v4l2_subdev_link_validate(link);
>>> +     if (ret)
>>> +             return ret;
>>> +
>>> +     return isc_validate(isc);
>>> +}
>>> +
>>> +static const struct media_entity_operations isc_entity_operations = {
>>> +     .link_validate = isc_link_validate,
>>> +};
>>> +
>>>   int isc_mc_init(struct isc_device *isc, u32 ver)
>>>   {
>>>        const struct of_device_id *match;
>>> @@ -2023,6 +1977,8 @@ int isc_mc_init(struct isc_device *isc, u32 ver)
>>>
>>>        isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
>>>        isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
>>> +     isc->video_dev.entity.ops = &isc_entity_operations;
>>> +
>>>        isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>>
>>>        ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
>>> diff --git a/drivers/media/platform/atmel/atmel-isc-scaler.c b/drivers/media/platform/atmel/atmel-isc-scaler.c
>>> index a1ca4633787c..2b0621297dfe 100644
>>> --- a/drivers/media/platform/atmel/atmel-isc-scaler.c
>>> +++ b/drivers/media/platform/atmel/atmel-isc-scaler.c
>>> @@ -173,6 +173,10 @@ static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
>>>        .init_cfg = isc_scaler_init_cfg,
>>>   };
>>>
>>> +static const struct media_entity_operations isc_scaler_entity_ops = {
>>> +     .link_validate = v4l2_subdev_link_validate,
>>> +};
>>> +
>>>   static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
>>>        .pad = &isc_scaler_pad_ops,
>>>   };
>>> @@ -190,6 +194,7 @@ int isc_scaler_init(struct isc_device *isc)
>>>
>>>        isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>>>        isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
>>> +     isc->scaler_sd.entity.ops = &isc_scaler_entity_ops;
>>>        isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>>        isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
>>>
>>> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
>>> index f98f25a55e73..5b0100c8c245 100644
>>> --- a/drivers/media/platform/atmel/atmel-isc.h
>>> +++ b/drivers/media/platform/atmel/atmel-isc.h
>>> @@ -63,15 +63,16 @@ struct isc_subdev_entity {
>>>    * @cfa_baycfg:              If this format is RAW BAYER, indicate the type of bayer.
>>>                        this is either BGBG, RGRG, etc.
>>>    * @pfe_cfg0_bps:    Number of hardware data lines connected to the ISC
>>> + * @raw:             If the format is raw bayer.
>>>    */
>>>
>>>   struct isc_format {
>>>        u32     fourcc;
>>>        u32     mbus_code;
>>>        u32     cfa_baycfg;
>>> -
>>> -     bool    sd_support;
>>>        u32     pfe_cfg0_bps;
>>> +
>>> +     bool    raw;
>>>   };
>>>
>>>   /* Pipeline bitmap */
>>> @@ -216,8 +217,7 @@ enum isc_scaler_pads {
>>>    * @comp:            completion reference that signals frame completion
>>>    *
>>>    * @fmt:             current v42l format
>>> - * @user_formats:    list of formats that are supported and agreed with sd
>>> - * @num_user_formats:        how many formats are in user_formats
>>> + * @try_fmt:         current v4l2 try format
>>>    *
>>>    * @config:          current ISC format configuration
>>>    * @try_config:              the current ISC try format , not yet activated
>>> @@ -272,6 +272,7 @@ enum isc_scaler_pads {
>>>    * @formats_list_size:       size of formats_list array
>>>    * @pads:            media controller pads for isc video entity
>>>    * @mdev:            media device that is registered by the isc
>>> + * @mpipe:           media device pipeline used by the isc
>>>    * @remote_pad:              remote pad on the connected subdevice
>>>    * @scaler_sd:               subdevice for the scaler that isc registers
>>>    * @scaler_pads:     media controller pads for the scaler subdevice
>>> @@ -298,8 +299,7 @@ struct isc_device {
>>>        struct completion       comp;
>>>
>>>        struct v4l2_format      fmt;
>>> -     struct isc_format       **user_formats;
>>> -     unsigned int            num_user_formats;
>>> +     struct v4l2_format      try_fmt;
>>>
>>>        struct fmt_config       config;
>>>        struct fmt_config       try_config;
>>> @@ -369,6 +369,7 @@ struct isc_device {
>>>        struct {
>>>                struct media_pad                pads[ISC_PADS_NUM];
>>>                struct media_device             mdev;
>>> +             struct media_pipeline           mpipe;
>>>
>>>                u32                             remote_pad;
>>>        };
>>> diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>> index d96ee3373889..2a651e237193 100644
>>> --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>> +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>> @@ -80,20 +80,40 @@ static const struct isc_format sama5d2_controller_formats[] = {
>>>                .fourcc         = V4L2_PIX_FMT_Y10,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
>>> +             .raw            = true,
>>> +     }, {
>>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
>>> +             .raw            = true,
>>> +     }, {
>>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
>>> +             .raw            = true,
>>> +     }, {
>>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
>>> +             .raw            = true,
>>> +     }, {
>>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
>>> +             .raw            = true,
>>>        },
>>>   };
>>>
>>> diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>> index e07ae188c15f..a0d60cfdba7b 100644
>>> --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>> +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>> @@ -89,20 +89,40 @@ static const struct isc_format sama7g5_controller_formats[] = {
>>>                .fourcc         = V4L2_PIX_FMT_Y16,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
>>> +             .raw            = true,
>>>        }, {
>>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
>>> +             .raw            = true,
>>> +     }, {
>>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
>>> +             .raw            = true,
>>> +     }, {
>>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
>>> +             .raw            = true,
>>> +     }, {
>>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
>>> +             .raw            = true,
>>> +     }, {
>>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
>>> +             .raw            = true,
>>>        },
>>>   };
>>>
>>
>

Hello

On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
> > On 4/29/22 11:17 AM, Hans Verkuil wrote:
> >> On 10/03/2022 10:51, Eugen Hristev wrote:
> >>> As a top MC video driver, the atmel-isc should not propagate the format to the
> >>> subdevice, it should rather check at start_streaming() time if the subdev is properly
> >>> configured with a compatible format.
> >>> Removed the whole format finding logic, and reworked the format verification
> >>> at start_streaming time, such that the ISC will return an error if the subdevice
> >>> is not properly configured. To achieve this, media_pipeline_start
> >>> is called and a link_validate callback is created to check the formats.
> >>> With this being done, the module parameter 'sensor_preferred' makes no sense
> >>> anymore. The ISC should not decide which format the sensor is using. The
> >>> ISC should only cope with the situation and inform userspace if the streaming
> >>> is possible in the current configuration.
> >>> The redesign of the format propagation has also risen the question of the
> >>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
> >>> should only return the formats that are supported for this mbus_code.
> >>> Otherwise, the enumfmt will report all the formats that the ISC could output.
> >>> With this rework, the dynamic list of user formats is removed. It makes no
> >>> more sense to identify at complete time which formats the sensor could emit,
> >>> and add those into a separate dynamic list.
> >>> The ISC will start with a simple preconfigured default format, and at
> >>> link validate time, decide whether it can use the format that is configured
> >>> on the sink or not.
> >>>
> >>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> >>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> >>> ---
> >>> Changes in v9:
> >>> - isc_link_validate now static
> >>>
> >>> Changes in v7:
> >>> - minor typos as suggested by Jacopo
> >>> - small changes, reduce some indentation, modified an index, as suggested by
> >>> Jacopo
> >>>
> >>> Changes in v6:
> >>> - reworked a bit enum_fmt as suggested by Jacopo
> >>>
> >>> Changes in v5:
> >>> - removed user_formats dynamic list as it is now pointless
> >>> - greatly simplified the enum_fmt function
> >>> - removed some init code that was useless now
> >>>
> >>> Changes in v4:
> >>> - moved validation code into link_validate and used media_pipeline_start
> >>> - merged this patch with the enum_fmt patch which was previously in v3 of
> >>> the series
> >>>
> >>> Changes in v3:
> >>> - clamp to maximum resolution once the frame size from the subdev is found
> >>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
> >>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
> >>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
> >>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
> >>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
> >>>   5 files changed, 236 insertions(+), 234 deletions(-)
> >>>
> >>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
> >>> index ee1dda6707a0..fe2c0af58060 100644
> >>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
> >>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
> >>> @@ -36,11 +36,6 @@ static unsigned int debug;
> >>>   module_param(debug, int, 0644);
> >>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
> >>>
> >>> -static unsigned int sensor_preferred = 1;
> >>> -module_param(sensor_preferred, uint, 0644);
> >>> -MODULE_PARM_DESC(sensor_preferred,
> >>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
> >>> -
> >>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
> >>>        (((mbus_code) & 0xf000) == 0x3000)
> >>>
> >>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
> >>>        unsigned long flags;
> >>>        int ret;
> >>>
> >>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
> >>
> >> The pipeline validation is done in start_streaming, but I don't think that
> >> is the best place: if STREAMON is called before buffers are queued, then
> >> an invalid pipeline isn't discovered until enough buffers are queued to
> >> kick off start_streaming.
> >>
> >> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
> >>
> >> I think that is the correct time to do this.
> >
> > Hello Hans,
> >
> > Initially (v2, v3) I had this in streamon(). The problem that I faced at
> > that time was that streamoff was never called, so I could not call
> > media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
> > (see change log for v4) , and I did not face any more problems.

Yes indeed, seems I suggested to use media_pipeline_handler in a
comment on your v3

"at s_stream time your top driver calls media_pipeline_start()"

sorry about that, I should have looked around a bit more carefully and
notice most drivers do so at vb2 streamon

However I don't see media_pipeline_start being called at all in v3 of
the patch

>
> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
> isn't called), exynos4-is does the same, but it also checks the streaming state in
> the release() fop callback, so that would fix this problem. And vimc does this
> in stop_streaming.
>
> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
> to be called.

Are you suggesting to have vb2 to call media_pipeline_start() or is it
more complex than this ?

>
> I'd like to know what others think.
>
> Regards,
>
> 	Hans
>
> >
> > Eugen
> >
> >>
> >> Laurent, Jacopo, do you agree with that?
> >>
> >> I notice that quite a few other drivers do this in start_streaming as well,
> >> but I think it just weird that a QBUF can return EPIPE while STREAMON might
> >> succeed.
> >>
> >> Perhaps we need an optional vb2 validate() callback that is called by
> >> vb2_core_streamon() to validate the pipeline before streaming. That makes
> >> it easier to implement these checks rather than having to implement your
> >> own streamon ioctl.
> >>
> >> Regards,
> >>
> >>          Hans
> >>
> >>> +     if (ret)
> >>> +             goto err_pipeline_start;
> >>> +
> >>>        /* Enable stream on the sub device */
> >>>        ret = v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 1);
> >>>        if (ret && ret != -ENOIOCTLCMD) {
> >>> @@ -385,6 +384,9 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
> >>>        v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
> >>>
> >>>   err_start_stream:
> >>> +     media_pipeline_stop(&isc->video_dev.entity);
> >>> +
> >>> +err_pipeline_start:
> >>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
> >>>        list_for_each_entry(buf, &isc->dma_queue, list)
> >>>                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
> >>> @@ -423,6 +425,9 @@ static void isc_stop_streaming(struct vb2_queue *vq)
> >>>        if (ret && ret != -ENOIOCTLCMD)
> >>>                v4l2_err(&isc->v4l2_dev, "stream off failed in subdev\n");
> >>>
> >>> +     /* Stop media pipeline */
> >>> +     media_pipeline_stop(&isc->video_dev.entity);
> >>> +
> >>>        /* Release all active buffers */
> >>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
> >>>        if (unlikely(isc->cur_frm)) {
> >>> @@ -453,22 +458,6 @@ static void isc_buffer_queue(struct vb2_buffer *vb)
> >>>        spin_unlock_irqrestore(&isc->dma_queue_lock, flags);
> >>>   }
> >>>
> >>> -static struct isc_format *find_format_by_fourcc(struct isc_device *isc,
> >>> -                                              unsigned int fourcc)
> >>> -{
> >>> -     unsigned int num_formats = isc->num_user_formats;
> >>> -     struct isc_format *fmt;
> >>> -     unsigned int i;
> >>> -
> >>> -     for (i = 0; i < num_formats; i++) {
> >>> -             fmt = isc->user_formats[i];
> >>> -             if (fmt->fourcc == fourcc)
> >>> -                     return fmt;
> >>> -     }
> >>> -
> >>> -     return NULL;
> >>> -}
> >>> -
> >>>   static const struct vb2_ops isc_vb2_ops = {
> >>>        .queue_setup            = isc_queue_setup,
> >>>        .wait_prepare           = vb2_ops_wait_prepare,
> >>> @@ -497,23 +486,57 @@ static int isc_enum_fmt_vid_cap(struct file *file, void *priv,
> >>>   {
> >>>        struct isc_device *isc = video_drvdata(file);
> >>>        u32 index = f->index;
> >>> -     u32 i, supported_index;
> >>> +     u32 i, supported_index = 0;
> >>> +     struct isc_format *fmt;
> >>> +
> >>> +     /*
> >>> +      * If we are not asked a specific mbus_code, we have to report all
> >>> +      * the formats that we can output.
> >>> +      */
> >>> +     if (!f->mbus_code) {
> >>> +             if (index >= isc->controller_formats_size)
> >>> +                     return -EINVAL;
> >>>
> >>> -     if (index < isc->controller_formats_size) {
> >>>                f->pixelformat = isc->controller_formats[index].fourcc;
> >>> +
> >>> +             return 0;
> >>> +     }
> >>> +
> >>> +     /*
> >>> +      * If a specific mbus_code is requested, check if we support
> >>> +      * this mbus_code as input for the ISC.
> >>> +      * If it's supported, then we report the corresponding pixelformat
> >>> +      * as first possible option for the ISC.
> >>> +      * E.g. mbus MEDIA_BUS_FMT_YUYV8_2X8 and report
> >>> +      * 'YUYV' (YUYV 4:2:2)
> >>> +      */
> >>> +     fmt = isc_find_format_by_code(isc, f->mbus_code, &i);
> >>> +     if (!fmt)
> >>> +             return -EINVAL;
> >>> +
> >>> +     if (!index) {
> >>> +             f->pixelformat = fmt->fourcc;
> >>> +
> >>>                return 0;
> >>>        }
> >>>
> >>> -     index -= isc->controller_formats_size;
> >>> +     supported_index++;
> >>>
> >>> -     supported_index = 0;
> >>> +     /* If the index is not raw, we don't have anymore formats to report */
> >>> +     if (!ISC_IS_FORMAT_RAW(f->mbus_code))
> >>> +             return -EINVAL;
> >>>
> >>> -     for (i = 0; i < isc->formats_list_size; i++) {
> >>> -             if (!ISC_IS_FORMAT_RAW(isc->formats_list[i].mbus_code) ||
> >>> -                 !isc->formats_list[i].sd_support)
> >>> +     /*
> >>> +      * We are asked for a specific mbus code, which is raw.
> >>> +      * We have to search through the formats we can convert to.
> >>> +      * We have to skip the raw formats, we cannot convert to raw.
> >>> +      * E.g. 'AR12' (16-bit ARGB 4-4-4-4), 'AR15' (16-bit ARGB 1-5-5-5), etc.
> >>> +      */
> >>> +     for (i = 0; i < isc->controller_formats_size; i++) {
> >>> +             if (isc->controller_formats[i].raw)
> >>>                        continue;
> >>> -             if (supported_index == index) {
> >>> -                     f->pixelformat = isc->formats_list[i].fourcc;
> >>> +             if (index == supported_index) {
> >>> +                     f->pixelformat = isc->controller_formats[i].fourcc;
> >>>                        return 0;
> >>>                }
> >>>                supported_index++;
> >>> @@ -584,20 +607,30 @@ static int isc_try_validate_formats(struct isc_device *isc)
> >>>                break;
> >>>        default:
> >>>        /* any other different formats are not supported */
> >>> +             v4l2_err(&isc->v4l2_dev, "Requested unsupported format.\n");
> >>>                ret = -EINVAL;
> >>>        }
> >>>        v4l2_dbg(1, debug, &isc->v4l2_dev,
> >>>                 "Format validation, requested rgb=%u, yuv=%u, grey=%u, bayer=%u\n",
> >>>                 rgb, yuv, grey, bayer);
> >>>
> >>> -     /* we cannot output RAW if we do not receive RAW */
> >>> -     if ((bayer) && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
> >>> +     if (bayer &&
> >>> +         !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code)) {
> >>> +             v4l2_err(&isc->v4l2_dev, "Cannot output RAW if we do not receive RAW.\n");
> >>>                return -EINVAL;
> >>> +     }
> >>>
> >>> -     /* we cannot output GREY if we do not receive RAW/GREY */
> >>>        if (grey && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code) &&
> >>> -         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code))
> >>> +         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
> >>> +             v4l2_err(&isc->v4l2_dev, "Cannot output GREY if we do not receive RAW/GREY.\n");
> >>>                return -EINVAL;
> >>> +     }
> >>> +
> >>> +     if ((rgb || bayer || yuv) &&
> >>> +         ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
> >>> +             v4l2_err(&isc->v4l2_dev, "Cannot convert GREY to another format.\n");
> >>> +             return -EINVAL;
> >>> +     }
> >>>
> >>>        return ret;
> >>>   }
> >>> @@ -825,7 +858,7 @@ static void isc_try_fse(struct isc_device *isc,
> >>>         * If we do not know yet which format the subdev is using, we cannot
> >>>         * do anything.
> >>>         */
> >>> -     if (!isc->try_config.sd_format)
> >>> +     if (!isc->config.sd_format)
> >>>                return;
> >>>
> >>>        fse.code = isc->try_config.sd_format->mbus_code;
> >>> @@ -846,180 +879,140 @@ static void isc_try_fse(struct isc_device *isc,
> >>>        }
> >>>   }
> >>>
> >>> -static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
> >>> -                     u32 *code)
> >>> +static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f)
> >>>   {
> >>> -     int i;
> >>> -     struct isc_format *sd_fmt = NULL, *direct_fmt = NULL;
> >>>        struct v4l2_pix_format *pixfmt = &f->fmt.pix;
> >>> -     struct v4l2_subdev_pad_config pad_cfg = {};
> >>> -     struct v4l2_subdev_state pad_state = {
> >>> -             .pads = &pad_cfg
> >>> -             };
> >>> -     struct v4l2_subdev_format format = {
> >>> -             .which = V4L2_SUBDEV_FORMAT_TRY,
> >>> -     };
> >>> -     u32 mbus_code;
> >>> -     int ret;
> >>> -     bool rlp_dma_direct_dump = false;
> >>> +     unsigned int i;
> >>>
> >>>        if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> >>>                return -EINVAL;
> >>>
> >>> -     /* Step 1: find a RAW format that is supported */
> >>> -     for (i = 0; i < isc->num_user_formats; i++) {
> >>> -             if (ISC_IS_FORMAT_RAW(isc->user_formats[i]->mbus_code)) {
> >>> -                     sd_fmt = isc->user_formats[i];
> >>> +     isc->try_config.fourcc = isc->controller_formats[0].fourcc;
> >>> +
> >>> +     /* find if the format requested is supported */
> >>> +     for (i = 0; i < isc->controller_formats_size; i++)
> >>> +             if (isc->controller_formats[i].fourcc == pixfmt->pixelformat) {
> >>> +                     isc->try_config.fourcc = pixfmt->pixelformat;
> >>>                        break;
> >>>                }
> >>> -     }
> >>> -     /* Step 2: We can continue with this RAW format, or we can look
> >>> -      * for better: maybe sensor supports directly what we need.
> >>> -      */
> >>> -     direct_fmt = find_format_by_fourcc(isc, pixfmt->pixelformat);
> >>> -
> >>> -     /* Step 3: We have both. We decide given the module parameter which
> >>> -      * one to use.
> >>> -      */
> >>> -     if (direct_fmt && sd_fmt && sensor_preferred)
> >>> -             sd_fmt = direct_fmt;
> >>> -
> >>> -     /* Step 4: we do not have RAW but we have a direct format. Use it. */
> >>> -     if (direct_fmt && !sd_fmt)
> >>> -             sd_fmt = direct_fmt;
> >>> -
> >>> -     /* Step 5: if we are using a direct format, we need to package
> >>> -      * everything as 8 bit data and just dump it
> >>> -      */
> >>> -     if (sd_fmt == direct_fmt)
> >>> -             rlp_dma_direct_dump = true;
> >>> -
> >>> -     /* Step 6: We have no format. This can happen if the userspace
> >>> -      * requests some weird/invalid format.
> >>> -      * In this case, default to whatever we have
> >>> -      */
> >>> -     if (!sd_fmt && !direct_fmt) {
> >>> -             sd_fmt = isc->user_formats[isc->num_user_formats - 1];
> >>> -             v4l2_dbg(1, debug, &isc->v4l2_dev,
> >>> -                      "Sensor not supporting %.4s, using %.4s\n",
> >>> -                      (char *)&pixfmt->pixelformat, (char *)&sd_fmt->fourcc);
> >>> -     }
> >>> -
> >>> -     if (!sd_fmt) {
> >>> -             ret = -EINVAL;
> >>> -             goto isc_try_fmt_err;
> >>> -     }
> >>> -
> >>> -     /* Step 7: Print out what we decided for debugging */
> >>> -     v4l2_dbg(1, debug, &isc->v4l2_dev,
> >>> -              "Preferring to have sensor using format %.4s\n",
> >>> -              (char *)&sd_fmt->fourcc);
> >>>
> >>> -     /* Step 8: at this moment we decided which format the subdev will use */
> >>> -     isc->try_config.sd_format = sd_fmt;
> >>> +     isc_try_configure_rlp_dma(isc, false);
> >>>
> >>>        /* Limit to Atmel ISC hardware capabilities */
> >>> -     if (pixfmt->width > isc->max_width)
> >>> -             pixfmt->width = isc->max_width;
> >>> -     if (pixfmt->height > isc->max_height)
> >>> -             pixfmt->height = isc->max_height;
> >>> -
> >>> -     /*
> >>> -      * The mbus format is the one the subdev outputs.
> >>> -      * The pixels will be transferred in this format Sensor -> ISC
> >>> -      */
> >>> -     mbus_code = sd_fmt->mbus_code;
> >>> -
> >>> -     /*
> >>> -      * Validate formats. If the required format is not OK, default to raw.
> >>> -      */
> >>> -
> >>> -     isc->try_config.fourcc = pixfmt->pixelformat;
> >>> -
> >>> -     if (isc_try_validate_formats(isc)) {
> >>> -             pixfmt->pixelformat = isc->try_config.fourcc = sd_fmt->fourcc;
> >>> -             /* Re-try to validate the new format */
> >>> -             ret = isc_try_validate_formats(isc);
> >>> -             if (ret)
> >>> -                     goto isc_try_fmt_err;
> >>> -     }
> >>> -
> >>> -     ret = isc_try_configure_rlp_dma(isc, rlp_dma_direct_dump);
> >>> -     if (ret)
> >>> -             goto isc_try_fmt_err;
> >>> -
> >>> -     ret = isc_try_configure_pipeline(isc);
> >>> -     if (ret)
> >>> -             goto isc_try_fmt_err;
> >>> -
> >>> -     /* Obtain frame sizes if possible to have crop requirements ready */
> >>> -     isc_try_fse(isc, &pad_state);
> >>> -
> >>> -     v4l2_fill_mbus_format(&format.format, pixfmt, mbus_code);
> >>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, set_fmt,
> >>> -                            &pad_state, &format);
> >>> -     if (ret < 0)
> >>> -             goto isc_try_fmt_subdev_err;
> >>> -
> >>> -     v4l2_fill_pix_format(pixfmt, &format.format);
> >>> +     v4l_bound_align_image(&pixfmt->width, 16, isc->max_width, 0,
> >>> +                           &pixfmt->height, 16, isc->max_height, 0, 0);
> >>> +     /* If we did not find the requested format, we will fallback here */
> >>> +     pixfmt->pixelformat = isc->try_config.fourcc;
> >>> +     pixfmt->colorspace = V4L2_COLORSPACE_SRGB;
> >>> +     pixfmt->field = V4L2_FIELD_NONE;
> >>>
> >>> -     /* Limit to Atmel ISC hardware capabilities */
> >>> -     if (pixfmt->width > isc->max_width)
> >>> -             pixfmt->width = isc->max_width;
> >>> -     if (pixfmt->height > isc->max_height)
> >>> -             pixfmt->height = isc->max_height;
> >>>
> >>> -     pixfmt->field = V4L2_FIELD_NONE;
> >>>        pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
> >>>        pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
> >>>                             pixfmt->height;
> >>>
> >>> -     if (code)
> >>> -             *code = mbus_code;
> >>> +     isc->try_fmt = *f;
> >>>
> >>>        return 0;
> >>> +}
> >>>
> >>> -isc_try_fmt_err:
> >>> -     v4l2_err(&isc->v4l2_dev, "Could not find any possible format for a working pipeline\n");
> >>> -isc_try_fmt_subdev_err:
> >>> -     memset(&isc->try_config, 0, sizeof(isc->try_config));
> >>> +static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
> >>> +{
> >>> +     isc_try_fmt(isc, f);
> >>>
> >>> -     return ret;
> >>> +     /* make the try configuration active */
> >>> +     isc->config = isc->try_config;
> >>> +     isc->fmt = isc->try_fmt;
> >>> +
> >>> +     v4l2_dbg(1, debug, &isc->v4l2_dev, "ISC set_fmt to %.4s @%dx%d\n",
> >>> +              (char *)&f->fmt.pix.pixelformat,
> >>> +              f->fmt.pix.width, f->fmt.pix.height);
> >>> +
> >>> +     return 0;
> >>>   }
> >>>
> >>> -static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
> >>> +static int isc_validate(struct isc_device *isc)
> >>>   {
> >>> +     int ret;
> >>> +     int i;
> >>> +     struct isc_format *sd_fmt = NULL;
> >>> +     struct v4l2_pix_format *pixfmt = &isc->fmt.fmt.pix;
> >>>        struct v4l2_subdev_format format = {
> >>>                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
> >>> +             .pad = isc->remote_pad,
> >>> +     };
> >>> +     struct v4l2_subdev_pad_config pad_cfg = {};
> >>> +     struct v4l2_subdev_state pad_state = {
> >>> +             .pads = &pad_cfg,
> >>>        };
> >>> -     u32 mbus_code = 0;
> >>> -     int ret;
> >>>
> >>> -     ret = isc_try_fmt(isc, f, &mbus_code);
> >>> +     /* Get current format from subdev */
> >>> +     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, get_fmt, NULL,
> >>> +                            &format);
> >>>        if (ret)
> >>>                return ret;
> >>>
> >>> -     v4l2_fill_mbus_format(&format.format, &f->fmt.pix, mbus_code);
> >>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad,
> >>> -                            set_fmt, NULL, &format);
> >>> -     if (ret < 0)
> >>> -             return ret;
> >>> +     /* Identify the subdev's format configuration */
> >>> +     for (i = 0; i < isc->formats_list_size; i++)
> >>> +             if (isc->formats_list[i].mbus_code == format.format.code) {
> >>> +                     sd_fmt = &isc->formats_list[i];
> >>> +                     break;
> >>> +             }
> >>> +
> >>> +     /* Check if the format is not supported */
> >>> +     if (!sd_fmt) {
> >>> +             v4l2_err(&isc->v4l2_dev,
> >>> +                      "Current subdevice is streaming a media bus code that is not supported 0x%x\n",
> >>> +                      format.format.code);
> >>> +             return -EPIPE;
> >>> +     }
> >>> +
> >>> +     /* At this moment we know which format the subdev will use */
> >>> +     isc->try_config.sd_format = sd_fmt;
> >>> +
> >>> +     /* If the sensor is not RAW, we can only do a direct dump */
> >>> +     if (!ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
> >>> +             isc_try_configure_rlp_dma(isc, true);
> >>>
> >>>        /* Limit to Atmel ISC hardware capabilities */
> >>> -     if (f->fmt.pix.width > isc->max_width)
> >>> -             f->fmt.pix.width = isc->max_width;
> >>> -     if (f->fmt.pix.height > isc->max_height)
> >>> -             f->fmt.pix.height = isc->max_height;
> >>> +     v4l_bound_align_image(&format.format.width, 16, isc->max_width, 0,
> >>> +                           &format.format.height, 16, isc->max_height, 0, 0);
> >>>
> >>> -     isc->fmt = *f;
> >>> +     /* Check if the frame size is the same. Otherwise we may overflow */
> >>> +     if (pixfmt->height != format.format.height ||
> >>> +         pixfmt->width != format.format.width) {
> >>> +             v4l2_err(&isc->v4l2_dev,
> >>> +                      "ISC not configured with the proper frame size: %dx%d\n",
> >>> +                      format.format.width, format.format.height);
> >>> +             return -EPIPE;
> >>> +     }
> >>>
> >>> +     v4l2_dbg(1, debug, &isc->v4l2_dev,
> >>> +              "Identified subdev using format %.4s with %dx%d %d bpp\n",
> >>> +              (char *)&sd_fmt->fourcc, pixfmt->width, pixfmt->height,
> >>> +              isc->try_config.bpp);
> >>> +
> >>> +     /* Reset and restart AWB if the subdevice changed the format */
> >>>        if (isc->try_config.sd_format && isc->config.sd_format &&
> >>>            isc->try_config.sd_format != isc->config.sd_format) {
> >>>                isc->ctrls.hist_stat = HIST_INIT;
> >>>                isc_reset_awb_ctrls(isc);
> >>>                isc_update_v4l2_ctrls(isc);
> >>>        }
> >>> -     /* make the try configuration active */
> >>> +
> >>> +     /* Validate formats */
> >>> +     ret = isc_try_validate_formats(isc);
> >>> +     if (ret)
> >>> +             return ret;
> >>> +
> >>> +     /* Obtain frame sizes if possible to have crop requirements ready */
> >>> +     isc_try_fse(isc, &pad_state);
> >>> +
> >>> +     /* Configure ISC pipeline for the config */
> >>> +     ret = isc_try_configure_pipeline(isc);
> >>> +     if (ret)
> >>> +             return ret;
> >>> +
> >>>        isc->config = isc->try_config;
> >>>
> >>>        v4l2_dbg(1, debug, &isc->v4l2_dev, "New ISC configuration in place\n");
> >>> @@ -1043,7 +1036,7 @@ static int isc_try_fmt_vid_cap(struct file *file, void *priv,
> >>>   {
> >>>        struct isc_device *isc = video_drvdata(file);
> >>>
> >>> -     return isc_try_fmt(isc, f, NULL);
> >>> +     return isc_try_fmt(isc, f);
> >>>   }
> >>>
> >>>   static int isc_enum_input(struct file *file, void *priv,
> >>> @@ -1098,10 +1091,6 @@ static int isc_enum_framesizes(struct file *file, void *fh,
> >>>        if (fsize->index)
> >>>                return -EINVAL;
> >>>
> >>> -     for (i = 0; i < isc->num_user_formats; i++)
> >>> -             if (isc->user_formats[i]->fourcc == fsize->pixel_format)
> >>> -                     ret = 0;
> >>> -
> >>>        for (i = 0; i < isc->controller_formats_size; i++)
> >>>                if (isc->controller_formats[i].fourcc == fsize->pixel_format)
> >>>                        ret = 0;
> >>> @@ -1782,52 +1771,6 @@ struct isc_format *isc_find_format_by_code(struct isc_device *isc,
> >>>   }
> >>>   EXPORT_SYMBOL_GPL(isc_find_format_by_code);
> >>>
> >>> -static int isc_formats_init(struct isc_device *isc)
> >>> -{
> >>> -     struct isc_format *fmt;
> >>> -     struct v4l2_subdev *subdev = isc->current_subdev->sd;
> >>> -     unsigned int num_fmts, i, j;
> >>> -     u32 list_size = isc->formats_list_size;
> >>> -     struct v4l2_subdev_mbus_code_enum mbus_code = {
> >>> -             .which = V4L2_SUBDEV_FORMAT_ACTIVE,
> >>> -     };
> >>> -
> >>> -     num_fmts = 0;
> >>> -     while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
> >>> -            NULL, &mbus_code)) {
> >>> -             mbus_code.index++;
> >>> -
> >>> -             fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
> >>> -             if (!fmt) {
> >>> -                     v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
> >>> -                               mbus_code.code);
> >>> -                     continue;
> >>> -             }
> >>> -
> >>> -             fmt->sd_support = true;
> >>> -             num_fmts++;
> >>> -     }
> >>> -
> >>> -     if (!num_fmts)
> >>> -             return -ENXIO;
> >>> -
> >>> -     isc->num_user_formats = num_fmts;
> >>> -     isc->user_formats = devm_kcalloc(isc->dev,
> >>> -                                      num_fmts, sizeof(*isc->user_formats),
> >>> -                                      GFP_KERNEL);
> >>> -     if (!isc->user_formats)
> >>> -             return -ENOMEM;
> >>> -
> >>> -     fmt = &isc->formats_list[0];
> >>> -     for (i = 0, j = 0; i < list_size; i++) {
> >>> -             if (fmt->sd_support)
> >>> -                     isc->user_formats[j++] = fmt;
> >>> -             fmt++;
> >>> -     }
> >>> -
> >>> -     return 0;
> >>> -}
> >>> -
> >>>   static int isc_set_default_fmt(struct isc_device *isc)
> >>>   {
> >>>        struct v4l2_format f = {
> >>> @@ -1836,12 +1779,12 @@ static int isc_set_default_fmt(struct isc_device *isc)
> >>>                        .width          = VGA_WIDTH,
> >>>                        .height         = VGA_HEIGHT,
> >>>                        .field          = V4L2_FIELD_NONE,
> >>> -                     .pixelformat    = isc->user_formats[0]->fourcc,
> >>> +                     .pixelformat    = isc->controller_formats[0].fourcc,
> >>>                },
> >>>        };
> >>>        int ret;
> >>>
> >>> -     ret = isc_try_fmt(isc, &f, NULL);
> >>> +     ret = isc_try_fmt(isc, &f);
> >>>        if (ret)
> >>>                return ret;
> >>>
> >>> @@ -1896,13 +1839,6 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
> >>>        spin_lock_init(&isc->dma_queue_lock);
> >>>        spin_lock_init(&isc->awb_lock);
> >>>
> >>> -     ret = isc_formats_init(isc);
> >>> -     if (ret < 0) {
> >>> -             v4l2_err(&isc->v4l2_dev,
> >>> -                      "Init format failed: %d\n", ret);
> >>> -             goto isc_async_complete_err;
> >>> -     }
> >>> -
> >>>        ret = isc_set_default_fmt(isc);
> >>>        if (ret) {
> >>>                v4l2_err(&isc->v4l2_dev, "Could not set default format\n");
> >>> @@ -2016,6 +1952,24 @@ int isc_pipeline_init(struct isc_device *isc)
> >>>   }
> >>>   EXPORT_SYMBOL_GPL(isc_pipeline_init);
> >>>
> >>> +static int isc_link_validate(struct media_link *link)
> >>> +{
> >>> +     struct video_device *vdev =
> >>> +             media_entity_to_video_device(link->sink->entity);
> >>> +     struct isc_device *isc = video_get_drvdata(vdev);
> >>> +     int ret;
> >>> +
> >>> +     ret = v4l2_subdev_link_validate(link);
> >>> +     if (ret)
> >>> +             return ret;
> >>> +
> >>> +     return isc_validate(isc);
> >>> +}
> >>> +
> >>> +static const struct media_entity_operations isc_entity_operations = {
> >>> +     .link_validate = isc_link_validate,
> >>> +};
> >>> +
> >>>   int isc_mc_init(struct isc_device *isc, u32 ver)
> >>>   {
> >>>        const struct of_device_id *match;
> >>> @@ -2023,6 +1977,8 @@ int isc_mc_init(struct isc_device *isc, u32 ver)
> >>>
> >>>        isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
> >>>        isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
> >>> +     isc->video_dev.entity.ops = &isc_entity_operations;
> >>> +
> >>>        isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> >>>
> >>>        ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
> >>> diff --git a/drivers/media/platform/atmel/atmel-isc-scaler.c b/drivers/media/platform/atmel/atmel-isc-scaler.c
> >>> index a1ca4633787c..2b0621297dfe 100644
> >>> --- a/drivers/media/platform/atmel/atmel-isc-scaler.c
> >>> +++ b/drivers/media/platform/atmel/atmel-isc-scaler.c
> >>> @@ -173,6 +173,10 @@ static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
> >>>        .init_cfg = isc_scaler_init_cfg,
> >>>   };
> >>>
> >>> +static const struct media_entity_operations isc_scaler_entity_ops = {
> >>> +     .link_validate = v4l2_subdev_link_validate,
> >>> +};
> >>> +
> >>>   static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
> >>>        .pad = &isc_scaler_pad_ops,
> >>>   };
> >>> @@ -190,6 +194,7 @@ int isc_scaler_init(struct isc_device *isc)
> >>>
> >>>        isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> >>>        isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
> >>> +     isc->scaler_sd.entity.ops = &isc_scaler_entity_ops;
> >>>        isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> >>>        isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> >>>
> >>> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
> >>> index f98f25a55e73..5b0100c8c245 100644
> >>> --- a/drivers/media/platform/atmel/atmel-isc.h
> >>> +++ b/drivers/media/platform/atmel/atmel-isc.h
> >>> @@ -63,15 +63,16 @@ struct isc_subdev_entity {
> >>>    * @cfa_baycfg:              If this format is RAW BAYER, indicate the type of bayer.
> >>>                        this is either BGBG, RGRG, etc.
> >>>    * @pfe_cfg0_bps:    Number of hardware data lines connected to the ISC
> >>> + * @raw:             If the format is raw bayer.
> >>>    */
> >>>
> >>>   struct isc_format {
> >>>        u32     fourcc;
> >>>        u32     mbus_code;
> >>>        u32     cfa_baycfg;
> >>> -
> >>> -     bool    sd_support;
> >>>        u32     pfe_cfg0_bps;
> >>> +
> >>> +     bool    raw;
> >>>   };
> >>>
> >>>   /* Pipeline bitmap */
> >>> @@ -216,8 +217,7 @@ enum isc_scaler_pads {
> >>>    * @comp:            completion reference that signals frame completion
> >>>    *
> >>>    * @fmt:             current v42l format
> >>> - * @user_formats:    list of formats that are supported and agreed with sd
> >>> - * @num_user_formats:        how many formats are in user_formats
> >>> + * @try_fmt:         current v4l2 try format
> >>>    *
> >>>    * @config:          current ISC format configuration
> >>>    * @try_config:              the current ISC try format , not yet activated
> >>> @@ -272,6 +272,7 @@ enum isc_scaler_pads {
> >>>    * @formats_list_size:       size of formats_list array
> >>>    * @pads:            media controller pads for isc video entity
> >>>    * @mdev:            media device that is registered by the isc
> >>> + * @mpipe:           media device pipeline used by the isc
> >>>    * @remote_pad:              remote pad on the connected subdevice
> >>>    * @scaler_sd:               subdevice for the scaler that isc registers
> >>>    * @scaler_pads:     media controller pads for the scaler subdevice
> >>> @@ -298,8 +299,7 @@ struct isc_device {
> >>>        struct completion       comp;
> >>>
> >>>        struct v4l2_format      fmt;
> >>> -     struct isc_format       **user_formats;
> >>> -     unsigned int            num_user_formats;
> >>> +     struct v4l2_format      try_fmt;
> >>>
> >>>        struct fmt_config       config;
> >>>        struct fmt_config       try_config;
> >>> @@ -369,6 +369,7 @@ struct isc_device {
> >>>        struct {
> >>>                struct media_pad                pads[ISC_PADS_NUM];
> >>>                struct media_device             mdev;
> >>> +             struct media_pipeline           mpipe;
> >>>
> >>>                u32                             remote_pad;
> >>>        };
> >>> diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> >>> index d96ee3373889..2a651e237193 100644
> >>> --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> >>> +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> >>> @@ -80,20 +80,40 @@ static const struct isc_format sama5d2_controller_formats[] = {
> >>>                .fourcc         = V4L2_PIX_FMT_Y10,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
> >>> +             .raw            = true,
> >>> +     }, {
> >>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
> >>> +             .raw            = true,
> >>> +     }, {
> >>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
> >>> +             .raw            = true,
> >>> +     }, {
> >>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
> >>> +             .raw            = true,
> >>> +     }, {
> >>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
> >>> +             .raw            = true,
> >>>        },
> >>>   };
> >>>
> >>> diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> >>> index e07ae188c15f..a0d60cfdba7b 100644
> >>> --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> >>> +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> >>> @@ -89,20 +89,40 @@ static const struct isc_format sama7g5_controller_formats[] = {
> >>>                .fourcc         = V4L2_PIX_FMT_Y16,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
> >>> +             .raw            = true,
> >>>        }, {
> >>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
> >>> +             .raw            = true,
> >>> +     }, {
> >>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
> >>> +             .raw            = true,
> >>> +     }, {
> >>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
> >>> +             .raw            = true,
> >>> +     }, {
> >>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
> >>> +             .raw            = true,
> >>> +     }, {
> >>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
> >>> +             .raw            = true,
> >>>        },
> >>>   };
> >>>
> >>
> >
>

On 29/04/2022 11:58, Jacopo Mondi wrote:
> Hello
> 
> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
>> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
>>> On 4/29/22 11:17 AM, Hans Verkuil wrote:
>>>> On 10/03/2022 10:51, Eugen Hristev wrote:
>>>>> As a top MC video driver, the atmel-isc should not propagate the format to the
>>>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
>>>>> configured with a compatible format.
>>>>> Removed the whole format finding logic, and reworked the format verification
>>>>> at start_streaming time, such that the ISC will return an error if the subdevice
>>>>> is not properly configured. To achieve this, media_pipeline_start
>>>>> is called and a link_validate callback is created to check the formats.
>>>>> With this being done, the module parameter 'sensor_preferred' makes no sense
>>>>> anymore. The ISC should not decide which format the sensor is using. The
>>>>> ISC should only cope with the situation and inform userspace if the streaming
>>>>> is possible in the current configuration.
>>>>> The redesign of the format propagation has also risen the question of the
>>>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
>>>>> should only return the formats that are supported for this mbus_code.
>>>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
>>>>> With this rework, the dynamic list of user formats is removed. It makes no
>>>>> more sense to identify at complete time which formats the sensor could emit,
>>>>> and add those into a separate dynamic list.
>>>>> The ISC will start with a simple preconfigured default format, and at
>>>>> link validate time, decide whether it can use the format that is configured
>>>>> on the sink or not.
>>>>>
>>>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>>>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>>>>> ---
>>>>> Changes in v9:
>>>>> - isc_link_validate now static
>>>>>
>>>>> Changes in v7:
>>>>> - minor typos as suggested by Jacopo
>>>>> - small changes, reduce some indentation, modified an index, as suggested by
>>>>> Jacopo
>>>>>
>>>>> Changes in v6:
>>>>> - reworked a bit enum_fmt as suggested by Jacopo
>>>>>
>>>>> Changes in v5:
>>>>> - removed user_formats dynamic list as it is now pointless
>>>>> - greatly simplified the enum_fmt function
>>>>> - removed some init code that was useless now
>>>>>
>>>>> Changes in v4:
>>>>> - moved validation code into link_validate and used media_pipeline_start
>>>>> - merged this patch with the enum_fmt patch which was previously in v3 of
>>>>> the series
>>>>>
>>>>> Changes in v3:
>>>>> - clamp to maximum resolution once the frame size from the subdev is found
>>>>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>>>>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>>>>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>>>>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>>>>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>>>>>   5 files changed, 236 insertions(+), 234 deletions(-)
>>>>>
>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>> index ee1dda6707a0..fe2c0af58060 100644
>>>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>> @@ -36,11 +36,6 @@ static unsigned int debug;
>>>>>   module_param(debug, int, 0644);
>>>>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
>>>>>
>>>>> -static unsigned int sensor_preferred = 1;
>>>>> -module_param(sensor_preferred, uint, 0644);
>>>>> -MODULE_PARM_DESC(sensor_preferred,
>>>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>>>>> -
>>>>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
>>>>>        (((mbus_code) & 0xf000) == 0x3000)
>>>>>
>>>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>>>        unsigned long flags;
>>>>>        int ret;
>>>>>
>>>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
>>>>
>>>> The pipeline validation is done in start_streaming, but I don't think that
>>>> is the best place: if STREAMON is called before buffers are queued, then
>>>> an invalid pipeline isn't discovered until enough buffers are queued to
>>>> kick off start_streaming.
>>>>
>>>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
>>>>
>>>> I think that is the correct time to do this.
>>>
>>> Hello Hans,
>>>
>>> Initially (v2, v3) I had this in streamon(). The problem that I faced at
>>> that time was that streamoff was never called, so I could not call
>>> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
>>> (see change log for v4) , and I did not face any more problems.
> 
> Yes indeed, seems I suggested to use media_pipeline_handler in a
> comment on your v3
> 
> "at s_stream time your top driver calls media_pipeline_start()"
> 
> sorry about that, I should have looked around a bit more carefully and
> notice most drivers do so at vb2 streamon
> 
> However I don't see media_pipeline_start being called at all in v3 of
> the patch
> 
>>
>> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
>> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
>> isn't called), exynos4-is does the same, but it also checks the streaming state in
>> the release() fop callback, so that would fix this problem. And vimc does this
>> in stop_streaming.
>>
>> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
>> to be called.
> 
> Are you suggesting to have vb2 to call media_pipeline_start() or is it
> more complex than this ?

No, I don't think vb2 should do that. But it needs two new ops: pipeline_start/stop
(or some other name) that are called at VIDIOC_STREAMON time and when the streaming
stops (due to STREAMOFF or by closing the fh). The driver can then take appropriate
action, which will typically be calling media_pipeline_start/stop, but other checks
may also be needed at that time.

Regards,

	Hans

> 
>>
>> I'd like to know what others think.
>>
>> Regards,
>>
>> 	Hans
>>
>>>
>>> Eugen
>>>
>>>>
>>>> Laurent, Jacopo, do you agree with that?
>>>>
>>>> I notice that quite a few other drivers do this in start_streaming as well,
>>>> but I think it just weird that a QBUF can return EPIPE while STREAMON might
>>>> succeed.
>>>>
>>>> Perhaps we need an optional vb2 validate() callback that is called by
>>>> vb2_core_streamon() to validate the pipeline before streaming. That makes
>>>> it easier to implement these checks rather than having to implement your
>>>> own streamon ioctl.
>>>>
>>>> Regards,
>>>>
>>>>          Hans
>>>>
>>>>> +     if (ret)
>>>>> +             goto err_pipeline_start;
>>>>> +
>>>>>        /* Enable stream on the sub device */
>>>>>        ret = v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 1);
>>>>>        if (ret && ret != -ENOIOCTLCMD) {
>>>>> @@ -385,6 +384,9 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>>>        v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
>>>>>
>>>>>   err_start_stream:
>>>>> +     media_pipeline_stop(&isc->video_dev.entity);
>>>>> +
>>>>> +err_pipeline_start:
>>>>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
>>>>>        list_for_each_entry(buf, &isc->dma_queue, list)
>>>>>                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
>>>>> @@ -423,6 +425,9 @@ static void isc_stop_streaming(struct vb2_queue *vq)
>>>>>        if (ret && ret != -ENOIOCTLCMD)
>>>>>                v4l2_err(&isc->v4l2_dev, "stream off failed in subdev\n");
>>>>>
>>>>> +     /* Stop media pipeline */
>>>>> +     media_pipeline_stop(&isc->video_dev.entity);
>>>>> +
>>>>>        /* Release all active buffers */
>>>>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
>>>>>        if (unlikely(isc->cur_frm)) {
>>>>> @@ -453,22 +458,6 @@ static void isc_buffer_queue(struct vb2_buffer *vb)
>>>>>        spin_unlock_irqrestore(&isc->dma_queue_lock, flags);
>>>>>   }
>>>>>
>>>>> -static struct isc_format *find_format_by_fourcc(struct isc_device *isc,
>>>>> -                                              unsigned int fourcc)
>>>>> -{
>>>>> -     unsigned int num_formats = isc->num_user_formats;
>>>>> -     struct isc_format *fmt;
>>>>> -     unsigned int i;
>>>>> -
>>>>> -     for (i = 0; i < num_formats; i++) {
>>>>> -             fmt = isc->user_formats[i];
>>>>> -             if (fmt->fourcc == fourcc)
>>>>> -                     return fmt;
>>>>> -     }
>>>>> -
>>>>> -     return NULL;
>>>>> -}
>>>>> -
>>>>>   static const struct vb2_ops isc_vb2_ops = {
>>>>>        .queue_setup            = isc_queue_setup,
>>>>>        .wait_prepare           = vb2_ops_wait_prepare,
>>>>> @@ -497,23 +486,57 @@ static int isc_enum_fmt_vid_cap(struct file *file, void *priv,
>>>>>   {
>>>>>        struct isc_device *isc = video_drvdata(file);
>>>>>        u32 index = f->index;
>>>>> -     u32 i, supported_index;
>>>>> +     u32 i, supported_index = 0;
>>>>> +     struct isc_format *fmt;
>>>>> +
>>>>> +     /*
>>>>> +      * If we are not asked a specific mbus_code, we have to report all
>>>>> +      * the formats that we can output.
>>>>> +      */
>>>>> +     if (!f->mbus_code) {
>>>>> +             if (index >= isc->controller_formats_size)
>>>>> +                     return -EINVAL;
>>>>>
>>>>> -     if (index < isc->controller_formats_size) {
>>>>>                f->pixelformat = isc->controller_formats[index].fourcc;
>>>>> +
>>>>> +             return 0;
>>>>> +     }
>>>>> +
>>>>> +     /*
>>>>> +      * If a specific mbus_code is requested, check if we support
>>>>> +      * this mbus_code as input for the ISC.
>>>>> +      * If it's supported, then we report the corresponding pixelformat
>>>>> +      * as first possible option for the ISC.
>>>>> +      * E.g. mbus MEDIA_BUS_FMT_YUYV8_2X8 and report
>>>>> +      * 'YUYV' (YUYV 4:2:2)
>>>>> +      */
>>>>> +     fmt = isc_find_format_by_code(isc, f->mbus_code, &i);
>>>>> +     if (!fmt)
>>>>> +             return -EINVAL;
>>>>> +
>>>>> +     if (!index) {
>>>>> +             f->pixelformat = fmt->fourcc;
>>>>> +
>>>>>                return 0;
>>>>>        }
>>>>>
>>>>> -     index -= isc->controller_formats_size;
>>>>> +     supported_index++;
>>>>>
>>>>> -     supported_index = 0;
>>>>> +     /* If the index is not raw, we don't have anymore formats to report */
>>>>> +     if (!ISC_IS_FORMAT_RAW(f->mbus_code))
>>>>> +             return -EINVAL;
>>>>>
>>>>> -     for (i = 0; i < isc->formats_list_size; i++) {
>>>>> -             if (!ISC_IS_FORMAT_RAW(isc->formats_list[i].mbus_code) ||
>>>>> -                 !isc->formats_list[i].sd_support)
>>>>> +     /*
>>>>> +      * We are asked for a specific mbus code, which is raw.
>>>>> +      * We have to search through the formats we can convert to.
>>>>> +      * We have to skip the raw formats, we cannot convert to raw.
>>>>> +      * E.g. 'AR12' (16-bit ARGB 4-4-4-4), 'AR15' (16-bit ARGB 1-5-5-5), etc.
>>>>> +      */
>>>>> +     for (i = 0; i < isc->controller_formats_size; i++) {
>>>>> +             if (isc->controller_formats[i].raw)
>>>>>                        continue;
>>>>> -             if (supported_index == index) {
>>>>> -                     f->pixelformat = isc->formats_list[i].fourcc;
>>>>> +             if (index == supported_index) {
>>>>> +                     f->pixelformat = isc->controller_formats[i].fourcc;
>>>>>                        return 0;
>>>>>                }
>>>>>                supported_index++;
>>>>> @@ -584,20 +607,30 @@ static int isc_try_validate_formats(struct isc_device *isc)
>>>>>                break;
>>>>>        default:
>>>>>        /* any other different formats are not supported */
>>>>> +             v4l2_err(&isc->v4l2_dev, "Requested unsupported format.\n");
>>>>>                ret = -EINVAL;
>>>>>        }
>>>>>        v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>>>                 "Format validation, requested rgb=%u, yuv=%u, grey=%u, bayer=%u\n",
>>>>>                 rgb, yuv, grey, bayer);
>>>>>
>>>>> -     /* we cannot output RAW if we do not receive RAW */
>>>>> -     if ((bayer) && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>>>>> +     if (bayer &&
>>>>> +         !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code)) {
>>>>> +             v4l2_err(&isc->v4l2_dev, "Cannot output RAW if we do not receive RAW.\n");
>>>>>                return -EINVAL;
>>>>> +     }
>>>>>
>>>>> -     /* we cannot output GREY if we do not receive RAW/GREY */
>>>>>        if (grey && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code) &&
>>>>> -         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code))
>>>>> +         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>>>>> +             v4l2_err(&isc->v4l2_dev, "Cannot output GREY if we do not receive RAW/GREY.\n");
>>>>>                return -EINVAL;
>>>>> +     }
>>>>> +
>>>>> +     if ((rgb || bayer || yuv) &&
>>>>> +         ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>>>>> +             v4l2_err(&isc->v4l2_dev, "Cannot convert GREY to another format.\n");
>>>>> +             return -EINVAL;
>>>>> +     }
>>>>>
>>>>>        return ret;
>>>>>   }
>>>>> @@ -825,7 +858,7 @@ static void isc_try_fse(struct isc_device *isc,
>>>>>         * If we do not know yet which format the subdev is using, we cannot
>>>>>         * do anything.
>>>>>         */
>>>>> -     if (!isc->try_config.sd_format)
>>>>> +     if (!isc->config.sd_format)
>>>>>                return;
>>>>>
>>>>>        fse.code = isc->try_config.sd_format->mbus_code;
>>>>> @@ -846,180 +879,140 @@ static void isc_try_fse(struct isc_device *isc,
>>>>>        }
>>>>>   }
>>>>>
>>>>> -static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
>>>>> -                     u32 *code)
>>>>> +static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f)
>>>>>   {
>>>>> -     int i;
>>>>> -     struct isc_format *sd_fmt = NULL, *direct_fmt = NULL;
>>>>>        struct v4l2_pix_format *pixfmt = &f->fmt.pix;
>>>>> -     struct v4l2_subdev_pad_config pad_cfg = {};
>>>>> -     struct v4l2_subdev_state pad_state = {
>>>>> -             .pads = &pad_cfg
>>>>> -             };
>>>>> -     struct v4l2_subdev_format format = {
>>>>> -             .which = V4L2_SUBDEV_FORMAT_TRY,
>>>>> -     };
>>>>> -     u32 mbus_code;
>>>>> -     int ret;
>>>>> -     bool rlp_dma_direct_dump = false;
>>>>> +     unsigned int i;
>>>>>
>>>>>        if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>>>>>                return -EINVAL;
>>>>>
>>>>> -     /* Step 1: find a RAW format that is supported */
>>>>> -     for (i = 0; i < isc->num_user_formats; i++) {
>>>>> -             if (ISC_IS_FORMAT_RAW(isc->user_formats[i]->mbus_code)) {
>>>>> -                     sd_fmt = isc->user_formats[i];
>>>>> +     isc->try_config.fourcc = isc->controller_formats[0].fourcc;
>>>>> +
>>>>> +     /* find if the format requested is supported */
>>>>> +     for (i = 0; i < isc->controller_formats_size; i++)
>>>>> +             if (isc->controller_formats[i].fourcc == pixfmt->pixelformat) {
>>>>> +                     isc->try_config.fourcc = pixfmt->pixelformat;
>>>>>                        break;
>>>>>                }
>>>>> -     }
>>>>> -     /* Step 2: We can continue with this RAW format, or we can look
>>>>> -      * for better: maybe sensor supports directly what we need.
>>>>> -      */
>>>>> -     direct_fmt = find_format_by_fourcc(isc, pixfmt->pixelformat);
>>>>> -
>>>>> -     /* Step 3: We have both. We decide given the module parameter which
>>>>> -      * one to use.
>>>>> -      */
>>>>> -     if (direct_fmt && sd_fmt && sensor_preferred)
>>>>> -             sd_fmt = direct_fmt;
>>>>> -
>>>>> -     /* Step 4: we do not have RAW but we have a direct format. Use it. */
>>>>> -     if (direct_fmt && !sd_fmt)
>>>>> -             sd_fmt = direct_fmt;
>>>>> -
>>>>> -     /* Step 5: if we are using a direct format, we need to package
>>>>> -      * everything as 8 bit data and just dump it
>>>>> -      */
>>>>> -     if (sd_fmt == direct_fmt)
>>>>> -             rlp_dma_direct_dump = true;
>>>>> -
>>>>> -     /* Step 6: We have no format. This can happen if the userspace
>>>>> -      * requests some weird/invalid format.
>>>>> -      * In this case, default to whatever we have
>>>>> -      */
>>>>> -     if (!sd_fmt && !direct_fmt) {
>>>>> -             sd_fmt = isc->user_formats[isc->num_user_formats - 1];
>>>>> -             v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>>> -                      "Sensor not supporting %.4s, using %.4s\n",
>>>>> -                      (char *)&pixfmt->pixelformat, (char *)&sd_fmt->fourcc);
>>>>> -     }
>>>>> -
>>>>> -     if (!sd_fmt) {
>>>>> -             ret = -EINVAL;
>>>>> -             goto isc_try_fmt_err;
>>>>> -     }
>>>>> -
>>>>> -     /* Step 7: Print out what we decided for debugging */
>>>>> -     v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>>> -              "Preferring to have sensor using format %.4s\n",
>>>>> -              (char *)&sd_fmt->fourcc);
>>>>>
>>>>> -     /* Step 8: at this moment we decided which format the subdev will use */
>>>>> -     isc->try_config.sd_format = sd_fmt;
>>>>> +     isc_try_configure_rlp_dma(isc, false);
>>>>>
>>>>>        /* Limit to Atmel ISC hardware capabilities */
>>>>> -     if (pixfmt->width > isc->max_width)
>>>>> -             pixfmt->width = isc->max_width;
>>>>> -     if (pixfmt->height > isc->max_height)
>>>>> -             pixfmt->height = isc->max_height;
>>>>> -
>>>>> -     /*
>>>>> -      * The mbus format is the one the subdev outputs.
>>>>> -      * The pixels will be transferred in this format Sensor -> ISC
>>>>> -      */
>>>>> -     mbus_code = sd_fmt->mbus_code;
>>>>> -
>>>>> -     /*
>>>>> -      * Validate formats. If the required format is not OK, default to raw.
>>>>> -      */
>>>>> -
>>>>> -     isc->try_config.fourcc = pixfmt->pixelformat;
>>>>> -
>>>>> -     if (isc_try_validate_formats(isc)) {
>>>>> -             pixfmt->pixelformat = isc->try_config.fourcc = sd_fmt->fourcc;
>>>>> -             /* Re-try to validate the new format */
>>>>> -             ret = isc_try_validate_formats(isc);
>>>>> -             if (ret)
>>>>> -                     goto isc_try_fmt_err;
>>>>> -     }
>>>>> -
>>>>> -     ret = isc_try_configure_rlp_dma(isc, rlp_dma_direct_dump);
>>>>> -     if (ret)
>>>>> -             goto isc_try_fmt_err;
>>>>> -
>>>>> -     ret = isc_try_configure_pipeline(isc);
>>>>> -     if (ret)
>>>>> -             goto isc_try_fmt_err;
>>>>> -
>>>>> -     /* Obtain frame sizes if possible to have crop requirements ready */
>>>>> -     isc_try_fse(isc, &pad_state);
>>>>> -
>>>>> -     v4l2_fill_mbus_format(&format.format, pixfmt, mbus_code);
>>>>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, set_fmt,
>>>>> -                            &pad_state, &format);
>>>>> -     if (ret < 0)
>>>>> -             goto isc_try_fmt_subdev_err;
>>>>> -
>>>>> -     v4l2_fill_pix_format(pixfmt, &format.format);
>>>>> +     v4l_bound_align_image(&pixfmt->width, 16, isc->max_width, 0,
>>>>> +                           &pixfmt->height, 16, isc->max_height, 0, 0);
>>>>> +     /* If we did not find the requested format, we will fallback here */
>>>>> +     pixfmt->pixelformat = isc->try_config.fourcc;
>>>>> +     pixfmt->colorspace = V4L2_COLORSPACE_SRGB;
>>>>> +     pixfmt->field = V4L2_FIELD_NONE;
>>>>>
>>>>> -     /* Limit to Atmel ISC hardware capabilities */
>>>>> -     if (pixfmt->width > isc->max_width)
>>>>> -             pixfmt->width = isc->max_width;
>>>>> -     if (pixfmt->height > isc->max_height)
>>>>> -             pixfmt->height = isc->max_height;
>>>>>
>>>>> -     pixfmt->field = V4L2_FIELD_NONE;
>>>>>        pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
>>>>>        pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
>>>>>                             pixfmt->height;
>>>>>
>>>>> -     if (code)
>>>>> -             *code = mbus_code;
>>>>> +     isc->try_fmt = *f;
>>>>>
>>>>>        return 0;
>>>>> +}
>>>>>
>>>>> -isc_try_fmt_err:
>>>>> -     v4l2_err(&isc->v4l2_dev, "Could not find any possible format for a working pipeline\n");
>>>>> -isc_try_fmt_subdev_err:
>>>>> -     memset(&isc->try_config, 0, sizeof(isc->try_config));
>>>>> +static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>>>>> +{
>>>>> +     isc_try_fmt(isc, f);
>>>>>
>>>>> -     return ret;
>>>>> +     /* make the try configuration active */
>>>>> +     isc->config = isc->try_config;
>>>>> +     isc->fmt = isc->try_fmt;
>>>>> +
>>>>> +     v4l2_dbg(1, debug, &isc->v4l2_dev, "ISC set_fmt to %.4s @%dx%d\n",
>>>>> +              (char *)&f->fmt.pix.pixelformat,
>>>>> +              f->fmt.pix.width, f->fmt.pix.height);
>>>>> +
>>>>> +     return 0;
>>>>>   }
>>>>>
>>>>> -static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>>>>> +static int isc_validate(struct isc_device *isc)
>>>>>   {
>>>>> +     int ret;
>>>>> +     int i;
>>>>> +     struct isc_format *sd_fmt = NULL;
>>>>> +     struct v4l2_pix_format *pixfmt = &isc->fmt.fmt.pix;
>>>>>        struct v4l2_subdev_format format = {
>>>>>                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>>>>> +             .pad = isc->remote_pad,
>>>>> +     };
>>>>> +     struct v4l2_subdev_pad_config pad_cfg = {};
>>>>> +     struct v4l2_subdev_state pad_state = {
>>>>> +             .pads = &pad_cfg,
>>>>>        };
>>>>> -     u32 mbus_code = 0;
>>>>> -     int ret;
>>>>>
>>>>> -     ret = isc_try_fmt(isc, f, &mbus_code);
>>>>> +     /* Get current format from subdev */
>>>>> +     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, get_fmt, NULL,
>>>>> +                            &format);
>>>>>        if (ret)
>>>>>                return ret;
>>>>>
>>>>> -     v4l2_fill_mbus_format(&format.format, &f->fmt.pix, mbus_code);
>>>>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad,
>>>>> -                            set_fmt, NULL, &format);
>>>>> -     if (ret < 0)
>>>>> -             return ret;
>>>>> +     /* Identify the subdev's format configuration */
>>>>> +     for (i = 0; i < isc->formats_list_size; i++)
>>>>> +             if (isc->formats_list[i].mbus_code == format.format.code) {
>>>>> +                     sd_fmt = &isc->formats_list[i];
>>>>> +                     break;
>>>>> +             }
>>>>> +
>>>>> +     /* Check if the format is not supported */
>>>>> +     if (!sd_fmt) {
>>>>> +             v4l2_err(&isc->v4l2_dev,
>>>>> +                      "Current subdevice is streaming a media bus code that is not supported 0x%x\n",
>>>>> +                      format.format.code);
>>>>> +             return -EPIPE;
>>>>> +     }
>>>>> +
>>>>> +     /* At this moment we know which format the subdev will use */
>>>>> +     isc->try_config.sd_format = sd_fmt;
>>>>> +
>>>>> +     /* If the sensor is not RAW, we can only do a direct dump */
>>>>> +     if (!ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>>>>> +             isc_try_configure_rlp_dma(isc, true);
>>>>>
>>>>>        /* Limit to Atmel ISC hardware capabilities */
>>>>> -     if (f->fmt.pix.width > isc->max_width)
>>>>> -             f->fmt.pix.width = isc->max_width;
>>>>> -     if (f->fmt.pix.height > isc->max_height)
>>>>> -             f->fmt.pix.height = isc->max_height;
>>>>> +     v4l_bound_align_image(&format.format.width, 16, isc->max_width, 0,
>>>>> +                           &format.format.height, 16, isc->max_height, 0, 0);
>>>>>
>>>>> -     isc->fmt = *f;
>>>>> +     /* Check if the frame size is the same. Otherwise we may overflow */
>>>>> +     if (pixfmt->height != format.format.height ||
>>>>> +         pixfmt->width != format.format.width) {
>>>>> +             v4l2_err(&isc->v4l2_dev,
>>>>> +                      "ISC not configured with the proper frame size: %dx%d\n",
>>>>> +                      format.format.width, format.format.height);
>>>>> +             return -EPIPE;
>>>>> +     }
>>>>>
>>>>> +     v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>>> +              "Identified subdev using format %.4s with %dx%d %d bpp\n",
>>>>> +              (char *)&sd_fmt->fourcc, pixfmt->width, pixfmt->height,
>>>>> +              isc->try_config.bpp);
>>>>> +
>>>>> +     /* Reset and restart AWB if the subdevice changed the format */
>>>>>        if (isc->try_config.sd_format && isc->config.sd_format &&
>>>>>            isc->try_config.sd_format != isc->config.sd_format) {
>>>>>                isc->ctrls.hist_stat = HIST_INIT;
>>>>>                isc_reset_awb_ctrls(isc);
>>>>>                isc_update_v4l2_ctrls(isc);
>>>>>        }
>>>>> -     /* make the try configuration active */
>>>>> +
>>>>> +     /* Validate formats */
>>>>> +     ret = isc_try_validate_formats(isc);
>>>>> +     if (ret)
>>>>> +             return ret;
>>>>> +
>>>>> +     /* Obtain frame sizes if possible to have crop requirements ready */
>>>>> +     isc_try_fse(isc, &pad_state);
>>>>> +
>>>>> +     /* Configure ISC pipeline for the config */
>>>>> +     ret = isc_try_configure_pipeline(isc);
>>>>> +     if (ret)
>>>>> +             return ret;
>>>>> +
>>>>>        isc->config = isc->try_config;
>>>>>
>>>>>        v4l2_dbg(1, debug, &isc->v4l2_dev, "New ISC configuration in place\n");
>>>>> @@ -1043,7 +1036,7 @@ static int isc_try_fmt_vid_cap(struct file *file, void *priv,
>>>>>   {
>>>>>        struct isc_device *isc = video_drvdata(file);
>>>>>
>>>>> -     return isc_try_fmt(isc, f, NULL);
>>>>> +     return isc_try_fmt(isc, f);
>>>>>   }
>>>>>
>>>>>   static int isc_enum_input(struct file *file, void *priv,
>>>>> @@ -1098,10 +1091,6 @@ static int isc_enum_framesizes(struct file *file, void *fh,
>>>>>        if (fsize->index)
>>>>>                return -EINVAL;
>>>>>
>>>>> -     for (i = 0; i < isc->num_user_formats; i++)
>>>>> -             if (isc->user_formats[i]->fourcc == fsize->pixel_format)
>>>>> -                     ret = 0;
>>>>> -
>>>>>        for (i = 0; i < isc->controller_formats_size; i++)
>>>>>                if (isc->controller_formats[i].fourcc == fsize->pixel_format)
>>>>>                        ret = 0;
>>>>> @@ -1782,52 +1771,6 @@ struct isc_format *isc_find_format_by_code(struct isc_device *isc,
>>>>>   }
>>>>>   EXPORT_SYMBOL_GPL(isc_find_format_by_code);
>>>>>
>>>>> -static int isc_formats_init(struct isc_device *isc)
>>>>> -{
>>>>> -     struct isc_format *fmt;
>>>>> -     struct v4l2_subdev *subdev = isc->current_subdev->sd;
>>>>> -     unsigned int num_fmts, i, j;
>>>>> -     u32 list_size = isc->formats_list_size;
>>>>> -     struct v4l2_subdev_mbus_code_enum mbus_code = {
>>>>> -             .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>>>>> -     };
>>>>> -
>>>>> -     num_fmts = 0;
>>>>> -     while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
>>>>> -            NULL, &mbus_code)) {
>>>>> -             mbus_code.index++;
>>>>> -
>>>>> -             fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
>>>>> -             if (!fmt) {
>>>>> -                     v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
>>>>> -                               mbus_code.code);
>>>>> -                     continue;
>>>>> -             }
>>>>> -
>>>>> -             fmt->sd_support = true;
>>>>> -             num_fmts++;
>>>>> -     }
>>>>> -
>>>>> -     if (!num_fmts)
>>>>> -             return -ENXIO;
>>>>> -
>>>>> -     isc->num_user_formats = num_fmts;
>>>>> -     isc->user_formats = devm_kcalloc(isc->dev,
>>>>> -                                      num_fmts, sizeof(*isc->user_formats),
>>>>> -                                      GFP_KERNEL);
>>>>> -     if (!isc->user_formats)
>>>>> -             return -ENOMEM;
>>>>> -
>>>>> -     fmt = &isc->formats_list[0];
>>>>> -     for (i = 0, j = 0; i < list_size; i++) {
>>>>> -             if (fmt->sd_support)
>>>>> -                     isc->user_formats[j++] = fmt;
>>>>> -             fmt++;
>>>>> -     }
>>>>> -
>>>>> -     return 0;
>>>>> -}
>>>>> -
>>>>>   static int isc_set_default_fmt(struct isc_device *isc)
>>>>>   {
>>>>>        struct v4l2_format f = {
>>>>> @@ -1836,12 +1779,12 @@ static int isc_set_default_fmt(struct isc_device *isc)
>>>>>                        .width          = VGA_WIDTH,
>>>>>                        .height         = VGA_HEIGHT,
>>>>>                        .field          = V4L2_FIELD_NONE,
>>>>> -                     .pixelformat    = isc->user_formats[0]->fourcc,
>>>>> +                     .pixelformat    = isc->controller_formats[0].fourcc,
>>>>>                },
>>>>>        };
>>>>>        int ret;
>>>>>
>>>>> -     ret = isc_try_fmt(isc, &f, NULL);
>>>>> +     ret = isc_try_fmt(isc, &f);
>>>>>        if (ret)
>>>>>                return ret;
>>>>>
>>>>> @@ -1896,13 +1839,6 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
>>>>>        spin_lock_init(&isc->dma_queue_lock);
>>>>>        spin_lock_init(&isc->awb_lock);
>>>>>
>>>>> -     ret = isc_formats_init(isc);
>>>>> -     if (ret < 0) {
>>>>> -             v4l2_err(&isc->v4l2_dev,
>>>>> -                      "Init format failed: %d\n", ret);
>>>>> -             goto isc_async_complete_err;
>>>>> -     }
>>>>> -
>>>>>        ret = isc_set_default_fmt(isc);
>>>>>        if (ret) {
>>>>>                v4l2_err(&isc->v4l2_dev, "Could not set default format\n");
>>>>> @@ -2016,6 +1952,24 @@ int isc_pipeline_init(struct isc_device *isc)
>>>>>   }
>>>>>   EXPORT_SYMBOL_GPL(isc_pipeline_init);
>>>>>
>>>>> +static int isc_link_validate(struct media_link *link)
>>>>> +{
>>>>> +     struct video_device *vdev =
>>>>> +             media_entity_to_video_device(link->sink->entity);
>>>>> +     struct isc_device *isc = video_get_drvdata(vdev);
>>>>> +     int ret;
>>>>> +
>>>>> +     ret = v4l2_subdev_link_validate(link);
>>>>> +     if (ret)
>>>>> +             return ret;
>>>>> +
>>>>> +     return isc_validate(isc);
>>>>> +}
>>>>> +
>>>>> +static const struct media_entity_operations isc_entity_operations = {
>>>>> +     .link_validate = isc_link_validate,
>>>>> +};
>>>>> +
>>>>>   int isc_mc_init(struct isc_device *isc, u32 ver)
>>>>>   {
>>>>>        const struct of_device_id *match;
>>>>> @@ -2023,6 +1977,8 @@ int isc_mc_init(struct isc_device *isc, u32 ver)
>>>>>
>>>>>        isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
>>>>>        isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
>>>>> +     isc->video_dev.entity.ops = &isc_entity_operations;
>>>>> +
>>>>>        isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>>>>
>>>>>        ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-scaler.c b/drivers/media/platform/atmel/atmel-isc-scaler.c
>>>>> index a1ca4633787c..2b0621297dfe 100644
>>>>> --- a/drivers/media/platform/atmel/atmel-isc-scaler.c
>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-scaler.c
>>>>> @@ -173,6 +173,10 @@ static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
>>>>>        .init_cfg = isc_scaler_init_cfg,
>>>>>   };
>>>>>
>>>>> +static const struct media_entity_operations isc_scaler_entity_ops = {
>>>>> +     .link_validate = v4l2_subdev_link_validate,
>>>>> +};
>>>>> +
>>>>>   static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
>>>>>        .pad = &isc_scaler_pad_ops,
>>>>>   };
>>>>> @@ -190,6 +194,7 @@ int isc_scaler_init(struct isc_device *isc)
>>>>>
>>>>>        isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>>>>>        isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
>>>>> +     isc->scaler_sd.entity.ops = &isc_scaler_entity_ops;
>>>>>        isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>>>>        isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
>>>>>
>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
>>>>> index f98f25a55e73..5b0100c8c245 100644
>>>>> --- a/drivers/media/platform/atmel/atmel-isc.h
>>>>> +++ b/drivers/media/platform/atmel/atmel-isc.h
>>>>> @@ -63,15 +63,16 @@ struct isc_subdev_entity {
>>>>>    * @cfa_baycfg:              If this format is RAW BAYER, indicate the type of bayer.
>>>>>                        this is either BGBG, RGRG, etc.
>>>>>    * @pfe_cfg0_bps:    Number of hardware data lines connected to the ISC
>>>>> + * @raw:             If the format is raw bayer.
>>>>>    */
>>>>>
>>>>>   struct isc_format {
>>>>>        u32     fourcc;
>>>>>        u32     mbus_code;
>>>>>        u32     cfa_baycfg;
>>>>> -
>>>>> -     bool    sd_support;
>>>>>        u32     pfe_cfg0_bps;
>>>>> +
>>>>> +     bool    raw;
>>>>>   };
>>>>>
>>>>>   /* Pipeline bitmap */
>>>>> @@ -216,8 +217,7 @@ enum isc_scaler_pads {
>>>>>    * @comp:            completion reference that signals frame completion
>>>>>    *
>>>>>    * @fmt:             current v42l format
>>>>> - * @user_formats:    list of formats that are supported and agreed with sd
>>>>> - * @num_user_formats:        how many formats are in user_formats
>>>>> + * @try_fmt:         current v4l2 try format
>>>>>    *
>>>>>    * @config:          current ISC format configuration
>>>>>    * @try_config:              the current ISC try format , not yet activated
>>>>> @@ -272,6 +272,7 @@ enum isc_scaler_pads {
>>>>>    * @formats_list_size:       size of formats_list array
>>>>>    * @pads:            media controller pads for isc video entity
>>>>>    * @mdev:            media device that is registered by the isc
>>>>> + * @mpipe:           media device pipeline used by the isc
>>>>>    * @remote_pad:              remote pad on the connected subdevice
>>>>>    * @scaler_sd:               subdevice for the scaler that isc registers
>>>>>    * @scaler_pads:     media controller pads for the scaler subdevice
>>>>> @@ -298,8 +299,7 @@ struct isc_device {
>>>>>        struct completion       comp;
>>>>>
>>>>>        struct v4l2_format      fmt;
>>>>> -     struct isc_format       **user_formats;
>>>>> -     unsigned int            num_user_formats;
>>>>> +     struct v4l2_format      try_fmt;
>>>>>
>>>>>        struct fmt_config       config;
>>>>>        struct fmt_config       try_config;
>>>>> @@ -369,6 +369,7 @@ struct isc_device {
>>>>>        struct {
>>>>>                struct media_pad                pads[ISC_PADS_NUM];
>>>>>                struct media_device             mdev;
>>>>> +             struct media_pipeline           mpipe;
>>>>>
>>>>>                u32                             remote_pad;
>>>>>        };
>>>>> diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>>>> index d96ee3373889..2a651e237193 100644
>>>>> --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>>>> +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>>>> @@ -80,20 +80,40 @@ static const struct isc_format sama5d2_controller_formats[] = {
>>>>>                .fourcc         = V4L2_PIX_FMT_Y10,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
>>>>> +             .raw            = true,
>>>>> +     }, {
>>>>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
>>>>> +             .raw            = true,
>>>>> +     }, {
>>>>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
>>>>> +             .raw            = true,
>>>>> +     }, {
>>>>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
>>>>> +             .raw            = true,
>>>>> +     }, {
>>>>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
>>>>> +             .raw            = true,
>>>>>        },
>>>>>   };
>>>>>
>>>>> diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>>>> index e07ae188c15f..a0d60cfdba7b 100644
>>>>> --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>>>> +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>>>> @@ -89,20 +89,40 @@ static const struct isc_format sama7g5_controller_formats[] = {
>>>>>                .fourcc         = V4L2_PIX_FMT_Y16,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
>>>>> +             .raw            = true,
>>>>>        }, {
>>>>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
>>>>> +             .raw            = true,
>>>>> +     }, {
>>>>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
>>>>> +             .raw            = true,
>>>>> +     }, {
>>>>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
>>>>> +             .raw            = true,
>>>>> +     }, {
>>>>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
>>>>> +             .raw            = true,
>>>>> +     }, {
>>>>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
>>>>> +             .raw            = true,
>>>>>        },
>>>>>   };
>>>>>
>>>>
>>>
>>

On Fri, Apr 29, 2022 at 11:58:48AM +0200, Jacopo Mondi wrote:
> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
> > On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
> > > On 4/29/22 11:17 AM, Hans Verkuil wrote:
> > >> On 10/03/2022 10:51, Eugen Hristev wrote:
> > >>> As a top MC video driver, the atmel-isc should not propagate the format to the
> > >>> subdevice, it should rather check at start_streaming() time if the subdev is properly
> > >>> configured with a compatible format.
> > >>> Removed the whole format finding logic, and reworked the format verification
> > >>> at start_streaming time, such that the ISC will return an error if the subdevice
> > >>> is not properly configured. To achieve this, media_pipeline_start
> > >>> is called and a link_validate callback is created to check the formats.
> > >>> With this being done, the module parameter 'sensor_preferred' makes no sense
> > >>> anymore. The ISC should not decide which format the sensor is using. The
> > >>> ISC should only cope with the situation and inform userspace if the streaming
> > >>> is possible in the current configuration.
> > >>> The redesign of the format propagation has also risen the question of the
> > >>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
> > >>> should only return the formats that are supported for this mbus_code.
> > >>> Otherwise, the enumfmt will report all the formats that the ISC could output.
> > >>> With this rework, the dynamic list of user formats is removed. It makes no
> > >>> more sense to identify at complete time which formats the sensor could emit,
> > >>> and add those into a separate dynamic list.
> > >>> The ISC will start with a simple preconfigured default format, and at
> > >>> link validate time, decide whether it can use the format that is configured
> > >>> on the sink or not.
> > >>>
> > >>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> > >>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> > >>> ---
> > >>> Changes in v9:
> > >>> - isc_link_validate now static
> > >>>
> > >>> Changes in v7:
> > >>> - minor typos as suggested by Jacopo
> > >>> - small changes, reduce some indentation, modified an index, as suggested by
> > >>> Jacopo
> > >>>
> > >>> Changes in v6:
> > >>> - reworked a bit enum_fmt as suggested by Jacopo
> > >>>
> > >>> Changes in v5:
> > >>> - removed user_formats dynamic list as it is now pointless
> > >>> - greatly simplified the enum_fmt function
> > >>> - removed some init code that was useless now
> > >>>
> > >>> Changes in v4:
> > >>> - moved validation code into link_validate and used media_pipeline_start
> > >>> - merged this patch with the enum_fmt patch which was previously in v3 of
> > >>> the series
> > >>>
> > >>> Changes in v3:
> > >>> - clamp to maximum resolution once the frame size from the subdev is found
> > >>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
> > >>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
> > >>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
> > >>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
> > >>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
> > >>>   5 files changed, 236 insertions(+), 234 deletions(-)
> > >>>
> > >>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
> > >>> index ee1dda6707a0..fe2c0af58060 100644
> > >>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
> > >>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
> > >>> @@ -36,11 +36,6 @@ static unsigned int debug;
> > >>>   module_param(debug, int, 0644);
> > >>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
> > >>>
> > >>> -static unsigned int sensor_preferred = 1;
> > >>> -module_param(sensor_preferred, uint, 0644);
> > >>> -MODULE_PARM_DESC(sensor_preferred,
> > >>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
> > >>> -
> > >>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
> > >>>        (((mbus_code) & 0xf000) == 0x3000)
> > >>>
> > >>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
> > >>>        unsigned long flags;
> > >>>        int ret;
> > >>>
> > >>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
> > >>
> > >> The pipeline validation is done in start_streaming, but I don't think that
> > >> is the best place: if STREAMON is called before buffers are queued, then
> > >> an invalid pipeline isn't discovered until enough buffers are queued to
> > >> kick off start_streaming.
> > >>
> > >> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
> > >>
> > >> I think that is the correct time to do this.
> > >
> > > Hello Hans,
> > >
> > > Initially (v2, v3) I had this in streamon(). The problem that I faced at
> > > that time was that streamoff was never called, so I could not call
> > > media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
> > > (see change log for v4) , and I did not face any more problems.
> 
> Yes indeed, seems I suggested to use media_pipeline_handler in a
> comment on your v3
> 
> "at s_stream time your top driver calls media_pipeline_start()"
> 
> sorry about that, I should have looked around a bit more carefully and
> notice most drivers do so at vb2 streamon
> 
> However I don't see media_pipeline_start being called at all in v3 of
> the patch
> 
> > It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
> > in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
> > isn't called), exynos4-is does the same, but it also checks the streaming state in
> > the release() fop callback, so that would fix this problem. And vimc does this
> > in stop_streaming.
> >
> > I'm in favor of fixing this in vb2, that framework knows exactly when this needs
> > to be called.
> 
> Are you suggesting to have vb2 to call media_pipeline_start() or is it
> more complex than this ?

I think Hans meant adding a .validate() operation to vb2.

vb2 is already quite complex, I don't think adding more features is a
good idea. I'd rather have vb2 focus on buffer management only
(.start_streaming() and .stop_streaming() shouldn't have been in there
in my opinion), and handle validation in the .streamon() handler. I'd
expect most drivers that deal with media pipelines to do more work in
.streamon() anyway.

> > I'd like to know what others think.
> >
> > >> Laurent, Jacopo, do you agree with that?
> > >>
> > >> I notice that quite a few other drivers do this in start_streaming as well,
> > >> but I think it just weird that a QBUF can return EPIPE while STREAMON might
> > >> succeed.
> > >>
> > >> Perhaps we need an optional vb2 validate() callback that is called by
> > >> vb2_core_streamon() to validate the pipeline before streaming. That makes
> > >> it easier to implement these checks rather than having to implement your
> > >> own streamon ioctl.
> > >>
> > >>> +     if (ret)
> > >>> +             goto err_pipeline_start;
> > >>> +
> > >>>        /* Enable stream on the sub device */
> > >>>        ret = v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 1);
> > >>>        if (ret && ret != -ENOIOCTLCMD) {
> > >>> @@ -385,6 +384,9 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
> > >>>        v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
> > >>>
> > >>>   err_start_stream:
> > >>> +     media_pipeline_stop(&isc->video_dev.entity);
> > >>> +
> > >>> +err_pipeline_start:
> > >>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
> > >>>        list_for_each_entry(buf, &isc->dma_queue, list)
> > >>>                vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
> > >>> @@ -423,6 +425,9 @@ static void isc_stop_streaming(struct vb2_queue *vq)
> > >>>        if (ret && ret != -ENOIOCTLCMD)
> > >>>                v4l2_err(&isc->v4l2_dev, "stream off failed in subdev\n");
> > >>>
> > >>> +     /* Stop media pipeline */
> > >>> +     media_pipeline_stop(&isc->video_dev.entity);
> > >>> +
> > >>>        /* Release all active buffers */
> > >>>        spin_lock_irqsave(&isc->dma_queue_lock, flags);
> > >>>        if (unlikely(isc->cur_frm)) {
> > >>> @@ -453,22 +458,6 @@ static void isc_buffer_queue(struct vb2_buffer *vb)
> > >>>        spin_unlock_irqrestore(&isc->dma_queue_lock, flags);
> > >>>   }
> > >>>
> > >>> -static struct isc_format *find_format_by_fourcc(struct isc_device *isc,
> > >>> -                                              unsigned int fourcc)
> > >>> -{
> > >>> -     unsigned int num_formats = isc->num_user_formats;
> > >>> -     struct isc_format *fmt;
> > >>> -     unsigned int i;
> > >>> -
> > >>> -     for (i = 0; i < num_formats; i++) {
> > >>> -             fmt = isc->user_formats[i];
> > >>> -             if (fmt->fourcc == fourcc)
> > >>> -                     return fmt;
> > >>> -     }
> > >>> -
> > >>> -     return NULL;
> > >>> -}
> > >>> -
> > >>>   static const struct vb2_ops isc_vb2_ops = {
> > >>>        .queue_setup            = isc_queue_setup,
> > >>>        .wait_prepare           = vb2_ops_wait_prepare,
> > >>> @@ -497,23 +486,57 @@ static int isc_enum_fmt_vid_cap(struct file *file, void *priv,
> > >>>   {
> > >>>        struct isc_device *isc = video_drvdata(file);
> > >>>        u32 index = f->index;
> > >>> -     u32 i, supported_index;
> > >>> +     u32 i, supported_index = 0;
> > >>> +     struct isc_format *fmt;
> > >>> +
> > >>> +     /*
> > >>> +      * If we are not asked a specific mbus_code, we have to report all
> > >>> +      * the formats that we can output.
> > >>> +      */
> > >>> +     if (!f->mbus_code) {
> > >>> +             if (index >= isc->controller_formats_size)
> > >>> +                     return -EINVAL;
> > >>>
> > >>> -     if (index < isc->controller_formats_size) {
> > >>>                f->pixelformat = isc->controller_formats[index].fourcc;
> > >>> +
> > >>> +             return 0;
> > >>> +     }
> > >>> +
> > >>> +     /*
> > >>> +      * If a specific mbus_code is requested, check if we support
> > >>> +      * this mbus_code as input for the ISC.
> > >>> +      * If it's supported, then we report the corresponding pixelformat
> > >>> +      * as first possible option for the ISC.
> > >>> +      * E.g. mbus MEDIA_BUS_FMT_YUYV8_2X8 and report
> > >>> +      * 'YUYV' (YUYV 4:2:2)
> > >>> +      */
> > >>> +     fmt = isc_find_format_by_code(isc, f->mbus_code, &i);
> > >>> +     if (!fmt)
> > >>> +             return -EINVAL;
> > >>> +
> > >>> +     if (!index) {
> > >>> +             f->pixelformat = fmt->fourcc;
> > >>> +
> > >>>                return 0;
> > >>>        }
> > >>>
> > >>> -     index -= isc->controller_formats_size;
> > >>> +     supported_index++;
> > >>>
> > >>> -     supported_index = 0;
> > >>> +     /* If the index is not raw, we don't have anymore formats to report */
> > >>> +     if (!ISC_IS_FORMAT_RAW(f->mbus_code))
> > >>> +             return -EINVAL;
> > >>>
> > >>> -     for (i = 0; i < isc->formats_list_size; i++) {
> > >>> -             if (!ISC_IS_FORMAT_RAW(isc->formats_list[i].mbus_code) ||
> > >>> -                 !isc->formats_list[i].sd_support)
> > >>> +     /*
> > >>> +      * We are asked for a specific mbus code, which is raw.
> > >>> +      * We have to search through the formats we can convert to.
> > >>> +      * We have to skip the raw formats, we cannot convert to raw.
> > >>> +      * E.g. 'AR12' (16-bit ARGB 4-4-4-4), 'AR15' (16-bit ARGB 1-5-5-5), etc.
> > >>> +      */
> > >>> +     for (i = 0; i < isc->controller_formats_size; i++) {
> > >>> +             if (isc->controller_formats[i].raw)
> > >>>                        continue;
> > >>> -             if (supported_index == index) {
> > >>> -                     f->pixelformat = isc->formats_list[i].fourcc;
> > >>> +             if (index == supported_index) {
> > >>> +                     f->pixelformat = isc->controller_formats[i].fourcc;
> > >>>                        return 0;
> > >>>                }
> > >>>                supported_index++;
> > >>> @@ -584,20 +607,30 @@ static int isc_try_validate_formats(struct isc_device *isc)
> > >>>                break;
> > >>>        default:
> > >>>        /* any other different formats are not supported */
> > >>> +             v4l2_err(&isc->v4l2_dev, "Requested unsupported format.\n");
> > >>>                ret = -EINVAL;
> > >>>        }
> > >>>        v4l2_dbg(1, debug, &isc->v4l2_dev,
> > >>>                 "Format validation, requested rgb=%u, yuv=%u, grey=%u, bayer=%u\n",
> > >>>                 rgb, yuv, grey, bayer);
> > >>>
> > >>> -     /* we cannot output RAW if we do not receive RAW */
> > >>> -     if ((bayer) && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
> > >>> +     if (bayer &&
> > >>> +         !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code)) {
> > >>> +             v4l2_err(&isc->v4l2_dev, "Cannot output RAW if we do not receive RAW.\n");
> > >>>                return -EINVAL;
> > >>> +     }
> > >>>
> > >>> -     /* we cannot output GREY if we do not receive RAW/GREY */
> > >>>        if (grey && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code) &&
> > >>> -         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code))
> > >>> +         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
> > >>> +             v4l2_err(&isc->v4l2_dev, "Cannot output GREY if we do not receive RAW/GREY.\n");
> > >>>                return -EINVAL;
> > >>> +     }
> > >>> +
> > >>> +     if ((rgb || bayer || yuv) &&
> > >>> +         ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
> > >>> +             v4l2_err(&isc->v4l2_dev, "Cannot convert GREY to another format.\n");
> > >>> +             return -EINVAL;
> > >>> +     }
> > >>>
> > >>>        return ret;
> > >>>   }
> > >>> @@ -825,7 +858,7 @@ static void isc_try_fse(struct isc_device *isc,
> > >>>         * If we do not know yet which format the subdev is using, we cannot
> > >>>         * do anything.
> > >>>         */
> > >>> -     if (!isc->try_config.sd_format)
> > >>> +     if (!isc->config.sd_format)
> > >>>                return;
> > >>>
> > >>>        fse.code = isc->try_config.sd_format->mbus_code;
> > >>> @@ -846,180 +879,140 @@ static void isc_try_fse(struct isc_device *isc,
> > >>>        }
> > >>>   }
> > >>>
> > >>> -static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
> > >>> -                     u32 *code)
> > >>> +static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f)
> > >>>   {
> > >>> -     int i;
> > >>> -     struct isc_format *sd_fmt = NULL, *direct_fmt = NULL;
> > >>>        struct v4l2_pix_format *pixfmt = &f->fmt.pix;
> > >>> -     struct v4l2_subdev_pad_config pad_cfg = {};
> > >>> -     struct v4l2_subdev_state pad_state = {
> > >>> -             .pads = &pad_cfg
> > >>> -             };
> > >>> -     struct v4l2_subdev_format format = {
> > >>> -             .which = V4L2_SUBDEV_FORMAT_TRY,
> > >>> -     };
> > >>> -     u32 mbus_code;
> > >>> -     int ret;
> > >>> -     bool rlp_dma_direct_dump = false;
> > >>> +     unsigned int i;
> > >>>
> > >>>        if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> > >>>                return -EINVAL;
> > >>>
> > >>> -     /* Step 1: find a RAW format that is supported */
> > >>> -     for (i = 0; i < isc->num_user_formats; i++) {
> > >>> -             if (ISC_IS_FORMAT_RAW(isc->user_formats[i]->mbus_code)) {
> > >>> -                     sd_fmt = isc->user_formats[i];
> > >>> +     isc->try_config.fourcc = isc->controller_formats[0].fourcc;
> > >>> +
> > >>> +     /* find if the format requested is supported */
> > >>> +     for (i = 0; i < isc->controller_formats_size; i++)
> > >>> +             if (isc->controller_formats[i].fourcc == pixfmt->pixelformat) {
> > >>> +                     isc->try_config.fourcc = pixfmt->pixelformat;
> > >>>                        break;
> > >>>                }
> > >>> -     }
> > >>> -     /* Step 2: We can continue with this RAW format, or we can look
> > >>> -      * for better: maybe sensor supports directly what we need.
> > >>> -      */
> > >>> -     direct_fmt = find_format_by_fourcc(isc, pixfmt->pixelformat);
> > >>> -
> > >>> -     /* Step 3: We have both. We decide given the module parameter which
> > >>> -      * one to use.
> > >>> -      */
> > >>> -     if (direct_fmt && sd_fmt && sensor_preferred)
> > >>> -             sd_fmt = direct_fmt;
> > >>> -
> > >>> -     /* Step 4: we do not have RAW but we have a direct format. Use it. */
> > >>> -     if (direct_fmt && !sd_fmt)
> > >>> -             sd_fmt = direct_fmt;
> > >>> -
> > >>> -     /* Step 5: if we are using a direct format, we need to package
> > >>> -      * everything as 8 bit data and just dump it
> > >>> -      */
> > >>> -     if (sd_fmt == direct_fmt)
> > >>> -             rlp_dma_direct_dump = true;
> > >>> -
> > >>> -     /* Step 6: We have no format. This can happen if the userspace
> > >>> -      * requests some weird/invalid format.
> > >>> -      * In this case, default to whatever we have
> > >>> -      */
> > >>> -     if (!sd_fmt && !direct_fmt) {
> > >>> -             sd_fmt = isc->user_formats[isc->num_user_formats - 1];
> > >>> -             v4l2_dbg(1, debug, &isc->v4l2_dev,
> > >>> -                      "Sensor not supporting %.4s, using %.4s\n",
> > >>> -                      (char *)&pixfmt->pixelformat, (char *)&sd_fmt->fourcc);
> > >>> -     }
> > >>> -
> > >>> -     if (!sd_fmt) {
> > >>> -             ret = -EINVAL;
> > >>> -             goto isc_try_fmt_err;
> > >>> -     }
> > >>> -
> > >>> -     /* Step 7: Print out what we decided for debugging */
> > >>> -     v4l2_dbg(1, debug, &isc->v4l2_dev,
> > >>> -              "Preferring to have sensor using format %.4s\n",
> > >>> -              (char *)&sd_fmt->fourcc);
> > >>>
> > >>> -     /* Step 8: at this moment we decided which format the subdev will use */
> > >>> -     isc->try_config.sd_format = sd_fmt;
> > >>> +     isc_try_configure_rlp_dma(isc, false);
> > >>>
> > >>>        /* Limit to Atmel ISC hardware capabilities */
> > >>> -     if (pixfmt->width > isc->max_width)
> > >>> -             pixfmt->width = isc->max_width;
> > >>> -     if (pixfmt->height > isc->max_height)
> > >>> -             pixfmt->height = isc->max_height;
> > >>> -
> > >>> -     /*
> > >>> -      * The mbus format is the one the subdev outputs.
> > >>> -      * The pixels will be transferred in this format Sensor -> ISC
> > >>> -      */
> > >>> -     mbus_code = sd_fmt->mbus_code;
> > >>> -
> > >>> -     /*
> > >>> -      * Validate formats. If the required format is not OK, default to raw.
> > >>> -      */
> > >>> -
> > >>> -     isc->try_config.fourcc = pixfmt->pixelformat;
> > >>> -
> > >>> -     if (isc_try_validate_formats(isc)) {
> > >>> -             pixfmt->pixelformat = isc->try_config.fourcc = sd_fmt->fourcc;
> > >>> -             /* Re-try to validate the new format */
> > >>> -             ret = isc_try_validate_formats(isc);
> > >>> -             if (ret)
> > >>> -                     goto isc_try_fmt_err;
> > >>> -     }
> > >>> -
> > >>> -     ret = isc_try_configure_rlp_dma(isc, rlp_dma_direct_dump);
> > >>> -     if (ret)
> > >>> -             goto isc_try_fmt_err;
> > >>> -
> > >>> -     ret = isc_try_configure_pipeline(isc);
> > >>> -     if (ret)
> > >>> -             goto isc_try_fmt_err;
> > >>> -
> > >>> -     /* Obtain frame sizes if possible to have crop requirements ready */
> > >>> -     isc_try_fse(isc, &pad_state);
> > >>> -
> > >>> -     v4l2_fill_mbus_format(&format.format, pixfmt, mbus_code);
> > >>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, set_fmt,
> > >>> -                            &pad_state, &format);
> > >>> -     if (ret < 0)
> > >>> -             goto isc_try_fmt_subdev_err;
> > >>> -
> > >>> -     v4l2_fill_pix_format(pixfmt, &format.format);
> > >>> +     v4l_bound_align_image(&pixfmt->width, 16, isc->max_width, 0,
> > >>> +                           &pixfmt->height, 16, isc->max_height, 0, 0);
> > >>> +     /* If we did not find the requested format, we will fallback here */
> > >>> +     pixfmt->pixelformat = isc->try_config.fourcc;
> > >>> +     pixfmt->colorspace = V4L2_COLORSPACE_SRGB;
> > >>> +     pixfmt->field = V4L2_FIELD_NONE;
> > >>>
> > >>> -     /* Limit to Atmel ISC hardware capabilities */
> > >>> -     if (pixfmt->width > isc->max_width)
> > >>> -             pixfmt->width = isc->max_width;
> > >>> -     if (pixfmt->height > isc->max_height)
> > >>> -             pixfmt->height = isc->max_height;
> > >>>
> > >>> -     pixfmt->field = V4L2_FIELD_NONE;
> > >>>        pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
> > >>>        pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
> > >>>                             pixfmt->height;
> > >>>
> > >>> -     if (code)
> > >>> -             *code = mbus_code;
> > >>> +     isc->try_fmt = *f;
> > >>>
> > >>>        return 0;
> > >>> +}
> > >>>
> > >>> -isc_try_fmt_err:
> > >>> -     v4l2_err(&isc->v4l2_dev, "Could not find any possible format for a working pipeline\n");
> > >>> -isc_try_fmt_subdev_err:
> > >>> -     memset(&isc->try_config, 0, sizeof(isc->try_config));
> > >>> +static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
> > >>> +{
> > >>> +     isc_try_fmt(isc, f);
> > >>>
> > >>> -     return ret;
> > >>> +     /* make the try configuration active */
> > >>> +     isc->config = isc->try_config;
> > >>> +     isc->fmt = isc->try_fmt;
> > >>> +
> > >>> +     v4l2_dbg(1, debug, &isc->v4l2_dev, "ISC set_fmt to %.4s @%dx%d\n",
> > >>> +              (char *)&f->fmt.pix.pixelformat,
> > >>> +              f->fmt.pix.width, f->fmt.pix.height);
> > >>> +
> > >>> +     return 0;
> > >>>   }
> > >>>
> > >>> -static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
> > >>> +static int isc_validate(struct isc_device *isc)
> > >>>   {
> > >>> +     int ret;
> > >>> +     int i;
> > >>> +     struct isc_format *sd_fmt = NULL;
> > >>> +     struct v4l2_pix_format *pixfmt = &isc->fmt.fmt.pix;
> > >>>        struct v4l2_subdev_format format = {
> > >>>                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
> > >>> +             .pad = isc->remote_pad,
> > >>> +     };
> > >>> +     struct v4l2_subdev_pad_config pad_cfg = {};
> > >>> +     struct v4l2_subdev_state pad_state = {
> > >>> +             .pads = &pad_cfg,
> > >>>        };
> > >>> -     u32 mbus_code = 0;
> > >>> -     int ret;
> > >>>
> > >>> -     ret = isc_try_fmt(isc, f, &mbus_code);
> > >>> +     /* Get current format from subdev */
> > >>> +     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, get_fmt, NULL,
> > >>> +                            &format);
> > >>>        if (ret)
> > >>>                return ret;
> > >>>
> > >>> -     v4l2_fill_mbus_format(&format.format, &f->fmt.pix, mbus_code);
> > >>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad,
> > >>> -                            set_fmt, NULL, &format);
> > >>> -     if (ret < 0)
> > >>> -             return ret;
> > >>> +     /* Identify the subdev's format configuration */
> > >>> +     for (i = 0; i < isc->formats_list_size; i++)
> > >>> +             if (isc->formats_list[i].mbus_code == format.format.code) {
> > >>> +                     sd_fmt = &isc->formats_list[i];
> > >>> +                     break;
> > >>> +             }
> > >>> +
> > >>> +     /* Check if the format is not supported */
> > >>> +     if (!sd_fmt) {
> > >>> +             v4l2_err(&isc->v4l2_dev,
> > >>> +                      "Current subdevice is streaming a media bus code that is not supported 0x%x\n",
> > >>> +                      format.format.code);
> > >>> +             return -EPIPE;
> > >>> +     }
> > >>> +
> > >>> +     /* At this moment we know which format the subdev will use */
> > >>> +     isc->try_config.sd_format = sd_fmt;
> > >>> +
> > >>> +     /* If the sensor is not RAW, we can only do a direct dump */
> > >>> +     if (!ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
> > >>> +             isc_try_configure_rlp_dma(isc, true);
> > >>>
> > >>>        /* Limit to Atmel ISC hardware capabilities */
> > >>> -     if (f->fmt.pix.width > isc->max_width)
> > >>> -             f->fmt.pix.width = isc->max_width;
> > >>> -     if (f->fmt.pix.height > isc->max_height)
> > >>> -             f->fmt.pix.height = isc->max_height;
> > >>> +     v4l_bound_align_image(&format.format.width, 16, isc->max_width, 0,
> > >>> +                           &format.format.height, 16, isc->max_height, 0, 0);
> > >>>
> > >>> -     isc->fmt = *f;
> > >>> +     /* Check if the frame size is the same. Otherwise we may overflow */
> > >>> +     if (pixfmt->height != format.format.height ||
> > >>> +         pixfmt->width != format.format.width) {
> > >>> +             v4l2_err(&isc->v4l2_dev,
> > >>> +                      "ISC not configured with the proper frame size: %dx%d\n",
> > >>> +                      format.format.width, format.format.height);
> > >>> +             return -EPIPE;
> > >>> +     }
> > >>>
> > >>> +     v4l2_dbg(1, debug, &isc->v4l2_dev,
> > >>> +              "Identified subdev using format %.4s with %dx%d %d bpp\n",
> > >>> +              (char *)&sd_fmt->fourcc, pixfmt->width, pixfmt->height,
> > >>> +              isc->try_config.bpp);
> > >>> +
> > >>> +     /* Reset and restart AWB if the subdevice changed the format */
> > >>>        if (isc->try_config.sd_format && isc->config.sd_format &&
> > >>>            isc->try_config.sd_format != isc->config.sd_format) {
> > >>>                isc->ctrls.hist_stat = HIST_INIT;
> > >>>                isc_reset_awb_ctrls(isc);
> > >>>                isc_update_v4l2_ctrls(isc);
> > >>>        }
> > >>> -     /* make the try configuration active */
> > >>> +
> > >>> +     /* Validate formats */
> > >>> +     ret = isc_try_validate_formats(isc);
> > >>> +     if (ret)
> > >>> +             return ret;
> > >>> +
> > >>> +     /* Obtain frame sizes if possible to have crop requirements ready */
> > >>> +     isc_try_fse(isc, &pad_state);
> > >>> +
> > >>> +     /* Configure ISC pipeline for the config */
> > >>> +     ret = isc_try_configure_pipeline(isc);
> > >>> +     if (ret)
> > >>> +             return ret;
> > >>> +
> > >>>        isc->config = isc->try_config;
> > >>>
> > >>>        v4l2_dbg(1, debug, &isc->v4l2_dev, "New ISC configuration in place\n");
> > >>> @@ -1043,7 +1036,7 @@ static int isc_try_fmt_vid_cap(struct file *file, void *priv,
> > >>>   {
> > >>>        struct isc_device *isc = video_drvdata(file);
> > >>>
> > >>> -     return isc_try_fmt(isc, f, NULL);
> > >>> +     return isc_try_fmt(isc, f);
> > >>>   }
> > >>>
> > >>>   static int isc_enum_input(struct file *file, void *priv,
> > >>> @@ -1098,10 +1091,6 @@ static int isc_enum_framesizes(struct file *file, void *fh,
> > >>>        if (fsize->index)
> > >>>                return -EINVAL;
> > >>>
> > >>> -     for (i = 0; i < isc->num_user_formats; i++)
> > >>> -             if (isc->user_formats[i]->fourcc == fsize->pixel_format)
> > >>> -                     ret = 0;
> > >>> -
> > >>>        for (i = 0; i < isc->controller_formats_size; i++)
> > >>>                if (isc->controller_formats[i].fourcc == fsize->pixel_format)
> > >>>                        ret = 0;
> > >>> @@ -1782,52 +1771,6 @@ struct isc_format *isc_find_format_by_code(struct isc_device *isc,
> > >>>   }
> > >>>   EXPORT_SYMBOL_GPL(isc_find_format_by_code);
> > >>>
> > >>> -static int isc_formats_init(struct isc_device *isc)
> > >>> -{
> > >>> -     struct isc_format *fmt;
> > >>> -     struct v4l2_subdev *subdev = isc->current_subdev->sd;
> > >>> -     unsigned int num_fmts, i, j;
> > >>> -     u32 list_size = isc->formats_list_size;
> > >>> -     struct v4l2_subdev_mbus_code_enum mbus_code = {
> > >>> -             .which = V4L2_SUBDEV_FORMAT_ACTIVE,
> > >>> -     };
> > >>> -
> > >>> -     num_fmts = 0;
> > >>> -     while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
> > >>> -            NULL, &mbus_code)) {
> > >>> -             mbus_code.index++;
> > >>> -
> > >>> -             fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
> > >>> -             if (!fmt) {
> > >>> -                     v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
> > >>> -                               mbus_code.code);
> > >>> -                     continue;
> > >>> -             }
> > >>> -
> > >>> -             fmt->sd_support = true;
> > >>> -             num_fmts++;
> > >>> -     }
> > >>> -
> > >>> -     if (!num_fmts)
> > >>> -             return -ENXIO;
> > >>> -
> > >>> -     isc->num_user_formats = num_fmts;
> > >>> -     isc->user_formats = devm_kcalloc(isc->dev,
> > >>> -                                      num_fmts, sizeof(*isc->user_formats),
> > >>> -                                      GFP_KERNEL);
> > >>> -     if (!isc->user_formats)
> > >>> -             return -ENOMEM;
> > >>> -
> > >>> -     fmt = &isc->formats_list[0];
> > >>> -     for (i = 0, j = 0; i < list_size; i++) {
> > >>> -             if (fmt->sd_support)
> > >>> -                     isc->user_formats[j++] = fmt;
> > >>> -             fmt++;
> > >>> -     }
> > >>> -
> > >>> -     return 0;
> > >>> -}
> > >>> -
> > >>>   static int isc_set_default_fmt(struct isc_device *isc)
> > >>>   {
> > >>>        struct v4l2_format f = {
> > >>> @@ -1836,12 +1779,12 @@ static int isc_set_default_fmt(struct isc_device *isc)
> > >>>                        .width          = VGA_WIDTH,
> > >>>                        .height         = VGA_HEIGHT,
> > >>>                        .field          = V4L2_FIELD_NONE,
> > >>> -                     .pixelformat    = isc->user_formats[0]->fourcc,
> > >>> +                     .pixelformat    = isc->controller_formats[0].fourcc,
> > >>>                },
> > >>>        };
> > >>>        int ret;
> > >>>
> > >>> -     ret = isc_try_fmt(isc, &f, NULL);
> > >>> +     ret = isc_try_fmt(isc, &f);
> > >>>        if (ret)
> > >>>                return ret;
> > >>>
> > >>> @@ -1896,13 +1839,6 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
> > >>>        spin_lock_init(&isc->dma_queue_lock);
> > >>>        spin_lock_init(&isc->awb_lock);
> > >>>
> > >>> -     ret = isc_formats_init(isc);
> > >>> -     if (ret < 0) {
> > >>> -             v4l2_err(&isc->v4l2_dev,
> > >>> -                      "Init format failed: %d\n", ret);
> > >>> -             goto isc_async_complete_err;
> > >>> -     }
> > >>> -
> > >>>        ret = isc_set_default_fmt(isc);
> > >>>        if (ret) {
> > >>>                v4l2_err(&isc->v4l2_dev, "Could not set default format\n");
> > >>> @@ -2016,6 +1952,24 @@ int isc_pipeline_init(struct isc_device *isc)
> > >>>   }
> > >>>   EXPORT_SYMBOL_GPL(isc_pipeline_init);
> > >>>
> > >>> +static int isc_link_validate(struct media_link *link)
> > >>> +{
> > >>> +     struct video_device *vdev =
> > >>> +             media_entity_to_video_device(link->sink->entity);
> > >>> +     struct isc_device *isc = video_get_drvdata(vdev);
> > >>> +     int ret;
> > >>> +
> > >>> +     ret = v4l2_subdev_link_validate(link);
> > >>> +     if (ret)
> > >>> +             return ret;
> > >>> +
> > >>> +     return isc_validate(isc);
> > >>> +}
> > >>> +
> > >>> +static const struct media_entity_operations isc_entity_operations = {
> > >>> +     .link_validate = isc_link_validate,
> > >>> +};
> > >>> +
> > >>>   int isc_mc_init(struct isc_device *isc, u32 ver)
> > >>>   {
> > >>>        const struct of_device_id *match;
> > >>> @@ -2023,6 +1977,8 @@ int isc_mc_init(struct isc_device *isc, u32 ver)
> > >>>
> > >>>        isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
> > >>>        isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
> > >>> +     isc->video_dev.entity.ops = &isc_entity_operations;
> > >>> +
> > >>>        isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> > >>>
> > >>>        ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
> > >>> diff --git a/drivers/media/platform/atmel/atmel-isc-scaler.c b/drivers/media/platform/atmel/atmel-isc-scaler.c
> > >>> index a1ca4633787c..2b0621297dfe 100644
> > >>> --- a/drivers/media/platform/atmel/atmel-isc-scaler.c
> > >>> +++ b/drivers/media/platform/atmel/atmel-isc-scaler.c
> > >>> @@ -173,6 +173,10 @@ static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
> > >>>        .init_cfg = isc_scaler_init_cfg,
> > >>>   };
> > >>>
> > >>> +static const struct media_entity_operations isc_scaler_entity_ops = {
> > >>> +     .link_validate = v4l2_subdev_link_validate,
> > >>> +};
> > >>> +
> > >>>   static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
> > >>>        .pad = &isc_scaler_pad_ops,
> > >>>   };
> > >>> @@ -190,6 +194,7 @@ int isc_scaler_init(struct isc_device *isc)
> > >>>
> > >>>        isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > >>>        isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
> > >>> +     isc->scaler_sd.entity.ops = &isc_scaler_entity_ops;
> > >>>        isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
> > >>>        isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
> > >>>
> > >>> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
> > >>> index f98f25a55e73..5b0100c8c245 100644
> > >>> --- a/drivers/media/platform/atmel/atmel-isc.h
> > >>> +++ b/drivers/media/platform/atmel/atmel-isc.h
> > >>> @@ -63,15 +63,16 @@ struct isc_subdev_entity {
> > >>>    * @cfa_baycfg:              If this format is RAW BAYER, indicate the type of bayer.
> > >>>                        this is either BGBG, RGRG, etc.
> > >>>    * @pfe_cfg0_bps:    Number of hardware data lines connected to the ISC
> > >>> + * @raw:             If the format is raw bayer.
> > >>>    */
> > >>>
> > >>>   struct isc_format {
> > >>>        u32     fourcc;
> > >>>        u32     mbus_code;
> > >>>        u32     cfa_baycfg;
> > >>> -
> > >>> -     bool    sd_support;
> > >>>        u32     pfe_cfg0_bps;
> > >>> +
> > >>> +     bool    raw;
> > >>>   };
> > >>>
> > >>>   /* Pipeline bitmap */
> > >>> @@ -216,8 +217,7 @@ enum isc_scaler_pads {
> > >>>    * @comp:            completion reference that signals frame completion
> > >>>    *
> > >>>    * @fmt:             current v42l format
> > >>> - * @user_formats:    list of formats that are supported and agreed with sd
> > >>> - * @num_user_formats:        how many formats are in user_formats
> > >>> + * @try_fmt:         current v4l2 try format
> > >>>    *
> > >>>    * @config:          current ISC format configuration
> > >>>    * @try_config:              the current ISC try format , not yet activated
> > >>> @@ -272,6 +272,7 @@ enum isc_scaler_pads {
> > >>>    * @formats_list_size:       size of formats_list array
> > >>>    * @pads:            media controller pads for isc video entity
> > >>>    * @mdev:            media device that is registered by the isc
> > >>> + * @mpipe:           media device pipeline used by the isc
> > >>>    * @remote_pad:              remote pad on the connected subdevice
> > >>>    * @scaler_sd:               subdevice for the scaler that isc registers
> > >>>    * @scaler_pads:     media controller pads for the scaler subdevice
> > >>> @@ -298,8 +299,7 @@ struct isc_device {
> > >>>        struct completion       comp;
> > >>>
> > >>>        struct v4l2_format      fmt;
> > >>> -     struct isc_format       **user_formats;
> > >>> -     unsigned int            num_user_formats;
> > >>> +     struct v4l2_format      try_fmt;
> > >>>
> > >>>        struct fmt_config       config;
> > >>>        struct fmt_config       try_config;
> > >>> @@ -369,6 +369,7 @@ struct isc_device {
> > >>>        struct {
> > >>>                struct media_pad                pads[ISC_PADS_NUM];
> > >>>                struct media_device             mdev;
> > >>> +             struct media_pipeline           mpipe;
> > >>>
> > >>>                u32                             remote_pad;
> > >>>        };
> > >>> diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> > >>> index d96ee3373889..2a651e237193 100644
> > >>> --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> > >>> +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
> > >>> @@ -80,20 +80,40 @@ static const struct isc_format sama5d2_controller_formats[] = {
> > >>>                .fourcc         = V4L2_PIX_FMT_Y10,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
> > >>> +             .raw            = true,
> > >>> +     }, {
> > >>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
> > >>> +             .raw            = true,
> > >>> +     }, {
> > >>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
> > >>> +             .raw            = true,
> > >>> +     }, {
> > >>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
> > >>> +             .raw            = true,
> > >>> +     }, {
> > >>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
> > >>> +             .raw            = true,
> > >>>        },
> > >>>   };
> > >>>
> > >>> diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> > >>> index e07ae188c15f..a0d60cfdba7b 100644
> > >>> --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> > >>> +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
> > >>> @@ -89,20 +89,40 @@ static const struct isc_format sama7g5_controller_formats[] = {
> > >>>                .fourcc         = V4L2_PIX_FMT_Y16,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SBGGR8,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SGBRG8,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SGRBG8,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SRGGB8,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SBGGR10,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SGBRG10,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SGRBG10,
> > >>> +             .raw            = true,
> > >>>        }, {
> > >>>                .fourcc         = V4L2_PIX_FMT_SRGGB10,
> > >>> +             .raw            = true,
> > >>> +     }, {
> > >>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
> > >>> +             .raw            = true,
> > >>> +     }, {
> > >>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
> > >>> +             .raw            = true,
> > >>> +     }, {
> > >>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
> > >>> +             .raw            = true,
> > >>> +     }, {
> > >>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
> > >>> +             .raw            = true,
> > >>>        },
> > >>>   };
> > >>>

On 4/29/22 1:03 PM, Hans Verkuil wrote:
> On 29/04/2022 11:58, Jacopo Mondi wrote:
>> Hello
>>
>> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
>>> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
>>>> On 4/29/22 11:17 AM, Hans Verkuil wrote:
>>>>> On 10/03/2022 10:51, Eugen Hristev wrote:
>>>>>> As a top MC video driver, the atmel-isc should not propagate the format to the
>>>>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
>>>>>> configured with a compatible format.
>>>>>> Removed the whole format finding logic, and reworked the format verification
>>>>>> at start_streaming time, such that the ISC will return an error if the subdevice
>>>>>> is not properly configured. To achieve this, media_pipeline_start
>>>>>> is called and a link_validate callback is created to check the formats.
>>>>>> With this being done, the module parameter 'sensor_preferred' makes no sense
>>>>>> anymore. The ISC should not decide which format the sensor is using. The
>>>>>> ISC should only cope with the situation and inform userspace if the streaming
>>>>>> is possible in the current configuration.
>>>>>> The redesign of the format propagation has also risen the question of the
>>>>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
>>>>>> should only return the formats that are supported for this mbus_code.
>>>>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
>>>>>> With this rework, the dynamic list of user formats is removed. It makes no
>>>>>> more sense to identify at complete time which formats the sensor could emit,
>>>>>> and add those into a separate dynamic list.
>>>>>> The ISC will start with a simple preconfigured default format, and at
>>>>>> link validate time, decide whether it can use the format that is configured
>>>>>> on the sink or not.
>>>>>>
>>>>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>>>>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>>>>>> ---
>>>>>> Changes in v9:
>>>>>> - isc_link_validate now static
>>>>>>
>>>>>> Changes in v7:
>>>>>> - minor typos as suggested by Jacopo
>>>>>> - small changes, reduce some indentation, modified an index, as suggested by
>>>>>> Jacopo
>>>>>>
>>>>>> Changes in v6:
>>>>>> - reworked a bit enum_fmt as suggested by Jacopo
>>>>>>
>>>>>> Changes in v5:
>>>>>> - removed user_formats dynamic list as it is now pointless
>>>>>> - greatly simplified the enum_fmt function
>>>>>> - removed some init code that was useless now
>>>>>>
>>>>>> Changes in v4:
>>>>>> - moved validation code into link_validate and used media_pipeline_start
>>>>>> - merged this patch with the enum_fmt patch which was previously in v3 of
>>>>>> the series
>>>>>>
>>>>>> Changes in v3:
>>>>>> - clamp to maximum resolution once the frame size from the subdev is found
>>>>>>    drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>>>>>>    .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>>>>>>    drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>>>>>>    .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>>>>>>    .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>>>>>>    5 files changed, 236 insertions(+), 234 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>> index ee1dda6707a0..fe2c0af58060 100644
>>>>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>> @@ -36,11 +36,6 @@ static unsigned int debug;
>>>>>>    module_param(debug, int, 0644);
>>>>>>    MODULE_PARM_DESC(debug, "debug level (0-2)");
>>>>>>
>>>>>> -static unsigned int sensor_preferred = 1;
>>>>>> -module_param(sensor_preferred, uint, 0644);
>>>>>> -MODULE_PARM_DESC(sensor_preferred,
>>>>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>>>>>> -
>>>>>>    #define ISC_IS_FORMAT_RAW(mbus_code) \
>>>>>>         (((mbus_code) & 0xf000) == 0x3000)
>>>>>>
>>>>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>>>>         unsigned long flags;
>>>>>>         int ret;
>>>>>>
>>>>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
>>>>>
>>>>> The pipeline validation is done in start_streaming, but I don't think that
>>>>> is the best place: if STREAMON is called before buffers are queued, then
>>>>> an invalid pipeline isn't discovered until enough buffers are queued to
>>>>> kick off start_streaming.
>>>>>
>>>>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
>>>>>
>>>>> I think that is the correct time to do this.
>>>>
>>>> Hello Hans,
>>>>
>>>> Initially (v2, v3) I had this in streamon(). The problem that I faced at
>>>> that time was that streamoff was never called, so I could not call
>>>> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
>>>> (see change log for v4) , and I did not face any more problems.
>>
>> Yes indeed, seems I suggested to use media_pipeline_handler in a
>> comment on your v3
>>
>> "at s_stream time your top driver calls media_pipeline_start()"
>>
>> sorry about that, I should have looked around a bit more carefully and
>> notice most drivers do so at vb2 streamon
>>
>> However I don't see media_pipeline_start being called at all in v3 of
>> the patch

No need to be sorry. Your suggestion was good and some other drivers do 
it, and it works well. We use this in production at the moment.
So thank you for that.

>>
>>>
>>> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
>>> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
>>> isn't called), exynos4-is does the same, but it also checks the streaming state in
>>> the release() fop callback, so that would fix this problem. And vimc does this
>>> in stop_streaming.
>>>
>>> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
>>> to be called.
>>
>> Are you suggesting to have vb2 to call media_pipeline_start() or is it
>> more complex than this ?
> 
> No, I don't think vb2 should do that. But it needs two new ops: pipeline_start/stop
> (or some other name) that are called at VIDIOC_STREAMON time and when the streaming
> stops (due to STREAMOFF or by closing the fh). The driver can then take appropriate
> action, which will typically be calling media_pipeline_start/stop, but other checks
> may also be needed at that time.

I can try to implement this and test with my driver, and come up with a 
proposal, if that is fine with you.


Eugen
> 
> Regards,
> 
>          Hans
> 
>>
>>>
>>> I'd like to know what others think.
>>>
>>> Regards,
>>>
>>>       Hans
>>>
>>>>
>>>> Eugen
>>>>
>>>>>
>>>>> Laurent, Jacopo, do you agree with that?
>>>>>
>>>>> I notice that quite a few other drivers do this in start_streaming as well,
>>>>> but I think it just weird that a QBUF can return EPIPE while STREAMON might
>>>>> succeed.
>>>>>
>>>>> Perhaps we need an optional vb2 validate() callback that is called by
>>>>> vb2_core_streamon() to validate the pipeline before streaming. That makes
>>>>> it easier to implement these checks rather than having to implement your
>>>>> own streamon ioctl.
>>>>>
>>>>> Regards,
>>>>>
>>>>>           Hans
>>>>>
>>>>>> +     if (ret)
>>>>>> +             goto err_pipeline_start;
>>>>>> +
>>>>>>         /* Enable stream on the sub device */
>>>>>>         ret = v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 1);
>>>>>>         if (ret && ret != -ENOIOCTLCMD) {
>>>>>> @@ -385,6 +384,9 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>>>>         v4l2_subdev_call(isc->current_subdev->sd, video, s_stream, 0);
>>>>>>
>>>>>>    err_start_stream:
>>>>>> +     media_pipeline_stop(&isc->video_dev.entity);
>>>>>> +
>>>>>> +err_pipeline_start:
>>>>>>         spin_lock_irqsave(&isc->dma_queue_lock, flags);
>>>>>>         list_for_each_entry(buf, &isc->dma_queue, list)
>>>>>>                 vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);
>>>>>> @@ -423,6 +425,9 @@ static void isc_stop_streaming(struct vb2_queue *vq)
>>>>>>         if (ret && ret != -ENOIOCTLCMD)
>>>>>>                 v4l2_err(&isc->v4l2_dev, "stream off failed in subdev\n");
>>>>>>
>>>>>> +     /* Stop media pipeline */
>>>>>> +     media_pipeline_stop(&isc->video_dev.entity);
>>>>>> +
>>>>>>         /* Release all active buffers */
>>>>>>         spin_lock_irqsave(&isc->dma_queue_lock, flags);
>>>>>>         if (unlikely(isc->cur_frm)) {
>>>>>> @@ -453,22 +458,6 @@ static void isc_buffer_queue(struct vb2_buffer *vb)
>>>>>>         spin_unlock_irqrestore(&isc->dma_queue_lock, flags);
>>>>>>    }
>>>>>>
>>>>>> -static struct isc_format *find_format_by_fourcc(struct isc_device *isc,
>>>>>> -                                              unsigned int fourcc)
>>>>>> -{
>>>>>> -     unsigned int num_formats = isc->num_user_formats;
>>>>>> -     struct isc_format *fmt;
>>>>>> -     unsigned int i;
>>>>>> -
>>>>>> -     for (i = 0; i < num_formats; i++) {
>>>>>> -             fmt = isc->user_formats[i];
>>>>>> -             if (fmt->fourcc == fourcc)
>>>>>> -                     return fmt;
>>>>>> -     }
>>>>>> -
>>>>>> -     return NULL;
>>>>>> -}
>>>>>> -
>>>>>>    static const struct vb2_ops isc_vb2_ops = {
>>>>>>         .queue_setup            = isc_queue_setup,
>>>>>>         .wait_prepare           = vb2_ops_wait_prepare,
>>>>>> @@ -497,23 +486,57 @@ static int isc_enum_fmt_vid_cap(struct file *file, void *priv,
>>>>>>    {
>>>>>>         struct isc_device *isc = video_drvdata(file);
>>>>>>         u32 index = f->index;
>>>>>> -     u32 i, supported_index;
>>>>>> +     u32 i, supported_index = 0;
>>>>>> +     struct isc_format *fmt;
>>>>>> +
>>>>>> +     /*
>>>>>> +      * If we are not asked a specific mbus_code, we have to report all
>>>>>> +      * the formats that we can output.
>>>>>> +      */
>>>>>> +     if (!f->mbus_code) {
>>>>>> +             if (index >= isc->controller_formats_size)
>>>>>> +                     return -EINVAL;
>>>>>>
>>>>>> -     if (index < isc->controller_formats_size) {
>>>>>>                 f->pixelformat = isc->controller_formats[index].fourcc;
>>>>>> +
>>>>>> +             return 0;
>>>>>> +     }
>>>>>> +
>>>>>> +     /*
>>>>>> +      * If a specific mbus_code is requested, check if we support
>>>>>> +      * this mbus_code as input for the ISC.
>>>>>> +      * If it's supported, then we report the corresponding pixelformat
>>>>>> +      * as first possible option for the ISC.
>>>>>> +      * E.g. mbus MEDIA_BUS_FMT_YUYV8_2X8 and report
>>>>>> +      * 'YUYV' (YUYV 4:2:2)
>>>>>> +      */
>>>>>> +     fmt = isc_find_format_by_code(isc, f->mbus_code, &i);
>>>>>> +     if (!fmt)
>>>>>> +             return -EINVAL;
>>>>>> +
>>>>>> +     if (!index) {
>>>>>> +             f->pixelformat = fmt->fourcc;
>>>>>> +
>>>>>>                 return 0;
>>>>>>         }
>>>>>>
>>>>>> -     index -= isc->controller_formats_size;
>>>>>> +     supported_index++;
>>>>>>
>>>>>> -     supported_index = 0;
>>>>>> +     /* If the index is not raw, we don't have anymore formats to report */
>>>>>> +     if (!ISC_IS_FORMAT_RAW(f->mbus_code))
>>>>>> +             return -EINVAL;
>>>>>>
>>>>>> -     for (i = 0; i < isc->formats_list_size; i++) {
>>>>>> -             if (!ISC_IS_FORMAT_RAW(isc->formats_list[i].mbus_code) ||
>>>>>> -                 !isc->formats_list[i].sd_support)
>>>>>> +     /*
>>>>>> +      * We are asked for a specific mbus code, which is raw.
>>>>>> +      * We have to search through the formats we can convert to.
>>>>>> +      * We have to skip the raw formats, we cannot convert to raw.
>>>>>> +      * E.g. 'AR12' (16-bit ARGB 4-4-4-4), 'AR15' (16-bit ARGB 1-5-5-5), etc.
>>>>>> +      */
>>>>>> +     for (i = 0; i < isc->controller_formats_size; i++) {
>>>>>> +             if (isc->controller_formats[i].raw)
>>>>>>                         continue;
>>>>>> -             if (supported_index == index) {
>>>>>> -                     f->pixelformat = isc->formats_list[i].fourcc;
>>>>>> +             if (index == supported_index) {
>>>>>> +                     f->pixelformat = isc->controller_formats[i].fourcc;
>>>>>>                         return 0;
>>>>>>                 }
>>>>>>                 supported_index++;
>>>>>> @@ -584,20 +607,30 @@ static int isc_try_validate_formats(struct isc_device *isc)
>>>>>>                 break;
>>>>>>         default:
>>>>>>         /* any other different formats are not supported */
>>>>>> +             v4l2_err(&isc->v4l2_dev, "Requested unsupported format.\n");
>>>>>>                 ret = -EINVAL;
>>>>>>         }
>>>>>>         v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>>>>                  "Format validation, requested rgb=%u, yuv=%u, grey=%u, bayer=%u\n",
>>>>>>                  rgb, yuv, grey, bayer);
>>>>>>
>>>>>> -     /* we cannot output RAW if we do not receive RAW */
>>>>>> -     if ((bayer) && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>>>>>> +     if (bayer &&
>>>>>> +         !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code)) {
>>>>>> +             v4l2_err(&isc->v4l2_dev, "Cannot output RAW if we do not receive RAW.\n");
>>>>>>                 return -EINVAL;
>>>>>> +     }
>>>>>>
>>>>>> -     /* we cannot output GREY if we do not receive RAW/GREY */
>>>>>>         if (grey && !ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code) &&
>>>>>> -         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code))
>>>>>> +         !ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>>>>>> +             v4l2_err(&isc->v4l2_dev, "Cannot output GREY if we do not receive RAW/GREY.\n");
>>>>>>                 return -EINVAL;
>>>>>> +     }
>>>>>> +
>>>>>> +     if ((rgb || bayer || yuv) &&
>>>>>> +         ISC_IS_FORMAT_GREY(isc->try_config.sd_format->mbus_code)) {
>>>>>> +             v4l2_err(&isc->v4l2_dev, "Cannot convert GREY to another format.\n");
>>>>>> +             return -EINVAL;
>>>>>> +     }
>>>>>>
>>>>>>         return ret;
>>>>>>    }
>>>>>> @@ -825,7 +858,7 @@ static void isc_try_fse(struct isc_device *isc,
>>>>>>          * If we do not know yet which format the subdev is using, we cannot
>>>>>>          * do anything.
>>>>>>          */
>>>>>> -     if (!isc->try_config.sd_format)
>>>>>> +     if (!isc->config.sd_format)
>>>>>>                 return;
>>>>>>
>>>>>>         fse.code = isc->try_config.sd_format->mbus_code;
>>>>>> @@ -846,180 +879,140 @@ static void isc_try_fse(struct isc_device *isc,
>>>>>>         }
>>>>>>    }
>>>>>>
>>>>>> -static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
>>>>>> -                     u32 *code)
>>>>>> +static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f)
>>>>>>    {
>>>>>> -     int i;
>>>>>> -     struct isc_format *sd_fmt = NULL, *direct_fmt = NULL;
>>>>>>         struct v4l2_pix_format *pixfmt = &f->fmt.pix;
>>>>>> -     struct v4l2_subdev_pad_config pad_cfg = {};
>>>>>> -     struct v4l2_subdev_state pad_state = {
>>>>>> -             .pads = &pad_cfg
>>>>>> -             };
>>>>>> -     struct v4l2_subdev_format format = {
>>>>>> -             .which = V4L2_SUBDEV_FORMAT_TRY,
>>>>>> -     };
>>>>>> -     u32 mbus_code;
>>>>>> -     int ret;
>>>>>> -     bool rlp_dma_direct_dump = false;
>>>>>> +     unsigned int i;
>>>>>>
>>>>>>         if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>>>>>>                 return -EINVAL;
>>>>>>
>>>>>> -     /* Step 1: find a RAW format that is supported */
>>>>>> -     for (i = 0; i < isc->num_user_formats; i++) {
>>>>>> -             if (ISC_IS_FORMAT_RAW(isc->user_formats[i]->mbus_code)) {
>>>>>> -                     sd_fmt = isc->user_formats[i];
>>>>>> +     isc->try_config.fourcc = isc->controller_formats[0].fourcc;
>>>>>> +
>>>>>> +     /* find if the format requested is supported */
>>>>>> +     for (i = 0; i < isc->controller_formats_size; i++)
>>>>>> +             if (isc->controller_formats[i].fourcc == pixfmt->pixelformat) {
>>>>>> +                     isc->try_config.fourcc = pixfmt->pixelformat;
>>>>>>                         break;
>>>>>>                 }
>>>>>> -     }
>>>>>> -     /* Step 2: We can continue with this RAW format, or we can look
>>>>>> -      * for better: maybe sensor supports directly what we need.
>>>>>> -      */
>>>>>> -     direct_fmt = find_format_by_fourcc(isc, pixfmt->pixelformat);
>>>>>> -
>>>>>> -     /* Step 3: We have both. We decide given the module parameter which
>>>>>> -      * one to use.
>>>>>> -      */
>>>>>> -     if (direct_fmt && sd_fmt && sensor_preferred)
>>>>>> -             sd_fmt = direct_fmt;
>>>>>> -
>>>>>> -     /* Step 4: we do not have RAW but we have a direct format. Use it. */
>>>>>> -     if (direct_fmt && !sd_fmt)
>>>>>> -             sd_fmt = direct_fmt;
>>>>>> -
>>>>>> -     /* Step 5: if we are using a direct format, we need to package
>>>>>> -      * everything as 8 bit data and just dump it
>>>>>> -      */
>>>>>> -     if (sd_fmt == direct_fmt)
>>>>>> -             rlp_dma_direct_dump = true;
>>>>>> -
>>>>>> -     /* Step 6: We have no format. This can happen if the userspace
>>>>>> -      * requests some weird/invalid format.
>>>>>> -      * In this case, default to whatever we have
>>>>>> -      */
>>>>>> -     if (!sd_fmt && !direct_fmt) {
>>>>>> -             sd_fmt = isc->user_formats[isc->num_user_formats - 1];
>>>>>> -             v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>>>> -                      "Sensor not supporting %.4s, using %.4s\n",
>>>>>> -                      (char *)&pixfmt->pixelformat, (char *)&sd_fmt->fourcc);
>>>>>> -     }
>>>>>> -
>>>>>> -     if (!sd_fmt) {
>>>>>> -             ret = -EINVAL;
>>>>>> -             goto isc_try_fmt_err;
>>>>>> -     }
>>>>>> -
>>>>>> -     /* Step 7: Print out what we decided for debugging */
>>>>>> -     v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>>>> -              "Preferring to have sensor using format %.4s\n",
>>>>>> -              (char *)&sd_fmt->fourcc);
>>>>>>
>>>>>> -     /* Step 8: at this moment we decided which format the subdev will use */
>>>>>> -     isc->try_config.sd_format = sd_fmt;
>>>>>> +     isc_try_configure_rlp_dma(isc, false);
>>>>>>
>>>>>>         /* Limit to Atmel ISC hardware capabilities */
>>>>>> -     if (pixfmt->width > isc->max_width)
>>>>>> -             pixfmt->width = isc->max_width;
>>>>>> -     if (pixfmt->height > isc->max_height)
>>>>>> -             pixfmt->height = isc->max_height;
>>>>>> -
>>>>>> -     /*
>>>>>> -      * The mbus format is the one the subdev outputs.
>>>>>> -      * The pixels will be transferred in this format Sensor -> ISC
>>>>>> -      */
>>>>>> -     mbus_code = sd_fmt->mbus_code;
>>>>>> -
>>>>>> -     /*
>>>>>> -      * Validate formats. If the required format is not OK, default to raw.
>>>>>> -      */
>>>>>> -
>>>>>> -     isc->try_config.fourcc = pixfmt->pixelformat;
>>>>>> -
>>>>>> -     if (isc_try_validate_formats(isc)) {
>>>>>> -             pixfmt->pixelformat = isc->try_config.fourcc = sd_fmt->fourcc;
>>>>>> -             /* Re-try to validate the new format */
>>>>>> -             ret = isc_try_validate_formats(isc);
>>>>>> -             if (ret)
>>>>>> -                     goto isc_try_fmt_err;
>>>>>> -     }
>>>>>> -
>>>>>> -     ret = isc_try_configure_rlp_dma(isc, rlp_dma_direct_dump);
>>>>>> -     if (ret)
>>>>>> -             goto isc_try_fmt_err;
>>>>>> -
>>>>>> -     ret = isc_try_configure_pipeline(isc);
>>>>>> -     if (ret)
>>>>>> -             goto isc_try_fmt_err;
>>>>>> -
>>>>>> -     /* Obtain frame sizes if possible to have crop requirements ready */
>>>>>> -     isc_try_fse(isc, &pad_state);
>>>>>> -
>>>>>> -     v4l2_fill_mbus_format(&format.format, pixfmt, mbus_code);
>>>>>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, set_fmt,
>>>>>> -                            &pad_state, &format);
>>>>>> -     if (ret < 0)
>>>>>> -             goto isc_try_fmt_subdev_err;
>>>>>> -
>>>>>> -     v4l2_fill_pix_format(pixfmt, &format.format);
>>>>>> +     v4l_bound_align_image(&pixfmt->width, 16, isc->max_width, 0,
>>>>>> +                           &pixfmt->height, 16, isc->max_height, 0, 0);
>>>>>> +     /* If we did not find the requested format, we will fallback here */
>>>>>> +     pixfmt->pixelformat = isc->try_config.fourcc;
>>>>>> +     pixfmt->colorspace = V4L2_COLORSPACE_SRGB;
>>>>>> +     pixfmt->field = V4L2_FIELD_NONE;
>>>>>>
>>>>>> -     /* Limit to Atmel ISC hardware capabilities */
>>>>>> -     if (pixfmt->width > isc->max_width)
>>>>>> -             pixfmt->width = isc->max_width;
>>>>>> -     if (pixfmt->height > isc->max_height)
>>>>>> -             pixfmt->height = isc->max_height;
>>>>>>
>>>>>> -     pixfmt->field = V4L2_FIELD_NONE;
>>>>>>         pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
>>>>>>         pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
>>>>>>                              pixfmt->height;
>>>>>>
>>>>>> -     if (code)
>>>>>> -             *code = mbus_code;
>>>>>> +     isc->try_fmt = *f;
>>>>>>
>>>>>>         return 0;
>>>>>> +}
>>>>>>
>>>>>> -isc_try_fmt_err:
>>>>>> -     v4l2_err(&isc->v4l2_dev, "Could not find any possible format for a working pipeline\n");
>>>>>> -isc_try_fmt_subdev_err:
>>>>>> -     memset(&isc->try_config, 0, sizeof(isc->try_config));
>>>>>> +static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>>>>>> +{
>>>>>> +     isc_try_fmt(isc, f);
>>>>>>
>>>>>> -     return ret;
>>>>>> +     /* make the try configuration active */
>>>>>> +     isc->config = isc->try_config;
>>>>>> +     isc->fmt = isc->try_fmt;
>>>>>> +
>>>>>> +     v4l2_dbg(1, debug, &isc->v4l2_dev, "ISC set_fmt to %.4s @%dx%d\n",
>>>>>> +              (char *)&f->fmt.pix.pixelformat,
>>>>>> +              f->fmt.pix.width, f->fmt.pix.height);
>>>>>> +
>>>>>> +     return 0;
>>>>>>    }
>>>>>>
>>>>>> -static int isc_set_fmt(struct isc_device *isc, struct v4l2_format *f)
>>>>>> +static int isc_validate(struct isc_device *isc)
>>>>>>    {
>>>>>> +     int ret;
>>>>>> +     int i;
>>>>>> +     struct isc_format *sd_fmt = NULL;
>>>>>> +     struct v4l2_pix_format *pixfmt = &isc->fmt.fmt.pix;
>>>>>>         struct v4l2_subdev_format format = {
>>>>>>                 .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>>>>>> +             .pad = isc->remote_pad,
>>>>>> +     };
>>>>>> +     struct v4l2_subdev_pad_config pad_cfg = {};
>>>>>> +     struct v4l2_subdev_state pad_state = {
>>>>>> +             .pads = &pad_cfg,
>>>>>>         };
>>>>>> -     u32 mbus_code = 0;
>>>>>> -     int ret;
>>>>>>
>>>>>> -     ret = isc_try_fmt(isc, f, &mbus_code);
>>>>>> +     /* Get current format from subdev */
>>>>>> +     ret = v4l2_subdev_call(isc->current_subdev->sd, pad, get_fmt, NULL,
>>>>>> +                            &format);
>>>>>>         if (ret)
>>>>>>                 return ret;
>>>>>>
>>>>>> -     v4l2_fill_mbus_format(&format.format, &f->fmt.pix, mbus_code);
>>>>>> -     ret = v4l2_subdev_call(isc->current_subdev->sd, pad,
>>>>>> -                            set_fmt, NULL, &format);
>>>>>> -     if (ret < 0)
>>>>>> -             return ret;
>>>>>> +     /* Identify the subdev's format configuration */
>>>>>> +     for (i = 0; i < isc->formats_list_size; i++)
>>>>>> +             if (isc->formats_list[i].mbus_code == format.format.code) {
>>>>>> +                     sd_fmt = &isc->formats_list[i];
>>>>>> +                     break;
>>>>>> +             }
>>>>>> +
>>>>>> +     /* Check if the format is not supported */
>>>>>> +     if (!sd_fmt) {
>>>>>> +             v4l2_err(&isc->v4l2_dev,
>>>>>> +                      "Current subdevice is streaming a media bus code that is not supported 0x%x\n",
>>>>>> +                      format.format.code);
>>>>>> +             return -EPIPE;
>>>>>> +     }
>>>>>> +
>>>>>> +     /* At this moment we know which format the subdev will use */
>>>>>> +     isc->try_config.sd_format = sd_fmt;
>>>>>> +
>>>>>> +     /* If the sensor is not RAW, we can only do a direct dump */
>>>>>> +     if (!ISC_IS_FORMAT_RAW(isc->try_config.sd_format->mbus_code))
>>>>>> +             isc_try_configure_rlp_dma(isc, true);
>>>>>>
>>>>>>         /* Limit to Atmel ISC hardware capabilities */
>>>>>> -     if (f->fmt.pix.width > isc->max_width)
>>>>>> -             f->fmt.pix.width = isc->max_width;
>>>>>> -     if (f->fmt.pix.height > isc->max_height)
>>>>>> -             f->fmt.pix.height = isc->max_height;
>>>>>> +     v4l_bound_align_image(&format.format.width, 16, isc->max_width, 0,
>>>>>> +                           &format.format.height, 16, isc->max_height, 0, 0);
>>>>>>
>>>>>> -     isc->fmt = *f;
>>>>>> +     /* Check if the frame size is the same. Otherwise we may overflow */
>>>>>> +     if (pixfmt->height != format.format.height ||
>>>>>> +         pixfmt->width != format.format.width) {
>>>>>> +             v4l2_err(&isc->v4l2_dev,
>>>>>> +                      "ISC not configured with the proper frame size: %dx%d\n",
>>>>>> +                      format.format.width, format.format.height);
>>>>>> +             return -EPIPE;
>>>>>> +     }
>>>>>>
>>>>>> +     v4l2_dbg(1, debug, &isc->v4l2_dev,
>>>>>> +              "Identified subdev using format %.4s with %dx%d %d bpp\n",
>>>>>> +              (char *)&sd_fmt->fourcc, pixfmt->width, pixfmt->height,
>>>>>> +              isc->try_config.bpp);
>>>>>> +
>>>>>> +     /* Reset and restart AWB if the subdevice changed the format */
>>>>>>         if (isc->try_config.sd_format && isc->config.sd_format &&
>>>>>>             isc->try_config.sd_format != isc->config.sd_format) {
>>>>>>                 isc->ctrls.hist_stat = HIST_INIT;
>>>>>>                 isc_reset_awb_ctrls(isc);
>>>>>>                 isc_update_v4l2_ctrls(isc);
>>>>>>         }
>>>>>> -     /* make the try configuration active */
>>>>>> +
>>>>>> +     /* Validate formats */
>>>>>> +     ret = isc_try_validate_formats(isc);
>>>>>> +     if (ret)
>>>>>> +             return ret;
>>>>>> +
>>>>>> +     /* Obtain frame sizes if possible to have crop requirements ready */
>>>>>> +     isc_try_fse(isc, &pad_state);
>>>>>> +
>>>>>> +     /* Configure ISC pipeline for the config */
>>>>>> +     ret = isc_try_configure_pipeline(isc);
>>>>>> +     if (ret)
>>>>>> +             return ret;
>>>>>> +
>>>>>>         isc->config = isc->try_config;
>>>>>>
>>>>>>         v4l2_dbg(1, debug, &isc->v4l2_dev, "New ISC configuration in place\n");
>>>>>> @@ -1043,7 +1036,7 @@ static int isc_try_fmt_vid_cap(struct file *file, void *priv,
>>>>>>    {
>>>>>>         struct isc_device *isc = video_drvdata(file);
>>>>>>
>>>>>> -     return isc_try_fmt(isc, f, NULL);
>>>>>> +     return isc_try_fmt(isc, f);
>>>>>>    }
>>>>>>
>>>>>>    static int isc_enum_input(struct file *file, void *priv,
>>>>>> @@ -1098,10 +1091,6 @@ static int isc_enum_framesizes(struct file *file, void *fh,
>>>>>>         if (fsize->index)
>>>>>>                 return -EINVAL;
>>>>>>
>>>>>> -     for (i = 0; i < isc->num_user_formats; i++)
>>>>>> -             if (isc->user_formats[i]->fourcc == fsize->pixel_format)
>>>>>> -                     ret = 0;
>>>>>> -
>>>>>>         for (i = 0; i < isc->controller_formats_size; i++)
>>>>>>                 if (isc->controller_formats[i].fourcc == fsize->pixel_format)
>>>>>>                         ret = 0;
>>>>>> @@ -1782,52 +1771,6 @@ struct isc_format *isc_find_format_by_code(struct isc_device *isc,
>>>>>>    }
>>>>>>    EXPORT_SYMBOL_GPL(isc_find_format_by_code);
>>>>>>
>>>>>> -static int isc_formats_init(struct isc_device *isc)
>>>>>> -{
>>>>>> -     struct isc_format *fmt;
>>>>>> -     struct v4l2_subdev *subdev = isc->current_subdev->sd;
>>>>>> -     unsigned int num_fmts, i, j;
>>>>>> -     u32 list_size = isc->formats_list_size;
>>>>>> -     struct v4l2_subdev_mbus_code_enum mbus_code = {
>>>>>> -             .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>>>>>> -     };
>>>>>> -
>>>>>> -     num_fmts = 0;
>>>>>> -     while (!v4l2_subdev_call(subdev, pad, enum_mbus_code,
>>>>>> -            NULL, &mbus_code)) {
>>>>>> -             mbus_code.index++;
>>>>>> -
>>>>>> -             fmt = isc_find_format_by_code(isc, mbus_code.code, &i);
>>>>>> -             if (!fmt) {
>>>>>> -                     v4l2_warn(&isc->v4l2_dev, "Mbus code %x not supported\n",
>>>>>> -                               mbus_code.code);
>>>>>> -                     continue;
>>>>>> -             }
>>>>>> -
>>>>>> -             fmt->sd_support = true;
>>>>>> -             num_fmts++;
>>>>>> -     }
>>>>>> -
>>>>>> -     if (!num_fmts)
>>>>>> -             return -ENXIO;
>>>>>> -
>>>>>> -     isc->num_user_formats = num_fmts;
>>>>>> -     isc->user_formats = devm_kcalloc(isc->dev,
>>>>>> -                                      num_fmts, sizeof(*isc->user_formats),
>>>>>> -                                      GFP_KERNEL);
>>>>>> -     if (!isc->user_formats)
>>>>>> -             return -ENOMEM;
>>>>>> -
>>>>>> -     fmt = &isc->formats_list[0];
>>>>>> -     for (i = 0, j = 0; i < list_size; i++) {
>>>>>> -             if (fmt->sd_support)
>>>>>> -                     isc->user_formats[j++] = fmt;
>>>>>> -             fmt++;
>>>>>> -     }
>>>>>> -
>>>>>> -     return 0;
>>>>>> -}
>>>>>> -
>>>>>>    static int isc_set_default_fmt(struct isc_device *isc)
>>>>>>    {
>>>>>>         struct v4l2_format f = {
>>>>>> @@ -1836,12 +1779,12 @@ static int isc_set_default_fmt(struct isc_device *isc)
>>>>>>                         .width          = VGA_WIDTH,
>>>>>>                         .height         = VGA_HEIGHT,
>>>>>>                         .field          = V4L2_FIELD_NONE,
>>>>>> -                     .pixelformat    = isc->user_formats[0]->fourcc,
>>>>>> +                     .pixelformat    = isc->controller_formats[0].fourcc,
>>>>>>                 },
>>>>>>         };
>>>>>>         int ret;
>>>>>>
>>>>>> -     ret = isc_try_fmt(isc, &f, NULL);
>>>>>> +     ret = isc_try_fmt(isc, &f);
>>>>>>         if (ret)
>>>>>>                 return ret;
>>>>>>
>>>>>> @@ -1896,13 +1839,6 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier)
>>>>>>         spin_lock_init(&isc->dma_queue_lock);
>>>>>>         spin_lock_init(&isc->awb_lock);
>>>>>>
>>>>>> -     ret = isc_formats_init(isc);
>>>>>> -     if (ret < 0) {
>>>>>> -             v4l2_err(&isc->v4l2_dev,
>>>>>> -                      "Init format failed: %d\n", ret);
>>>>>> -             goto isc_async_complete_err;
>>>>>> -     }
>>>>>> -
>>>>>>         ret = isc_set_default_fmt(isc);
>>>>>>         if (ret) {
>>>>>>                 v4l2_err(&isc->v4l2_dev, "Could not set default format\n");
>>>>>> @@ -2016,6 +1952,24 @@ int isc_pipeline_init(struct isc_device *isc)
>>>>>>    }
>>>>>>    EXPORT_SYMBOL_GPL(isc_pipeline_init);
>>>>>>
>>>>>> +static int isc_link_validate(struct media_link *link)
>>>>>> +{
>>>>>> +     struct video_device *vdev =
>>>>>> +             media_entity_to_video_device(link->sink->entity);
>>>>>> +     struct isc_device *isc = video_get_drvdata(vdev);
>>>>>> +     int ret;
>>>>>> +
>>>>>> +     ret = v4l2_subdev_link_validate(link);
>>>>>> +     if (ret)
>>>>>> +             return ret;
>>>>>> +
>>>>>> +     return isc_validate(isc);
>>>>>> +}
>>>>>> +
>>>>>> +static const struct media_entity_operations isc_entity_operations = {
>>>>>> +     .link_validate = isc_link_validate,
>>>>>> +};
>>>>>> +
>>>>>>    int isc_mc_init(struct isc_device *isc, u32 ver)
>>>>>>    {
>>>>>>         const struct of_device_id *match;
>>>>>> @@ -2023,6 +1977,8 @@ int isc_mc_init(struct isc_device *isc, u32 ver)
>>>>>>
>>>>>>         isc->video_dev.entity.function = MEDIA_ENT_F_IO_V4L;
>>>>>>         isc->video_dev.entity.flags = MEDIA_ENT_FL_DEFAULT;
>>>>>> +     isc->video_dev.entity.ops = &isc_entity_operations;
>>>>>> +
>>>>>>         isc->pads[ISC_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>>>>>
>>>>>>         ret = media_entity_pads_init(&isc->video_dev.entity, ISC_PADS_NUM,
>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-scaler.c b/drivers/media/platform/atmel/atmel-isc-scaler.c
>>>>>> index a1ca4633787c..2b0621297dfe 100644
>>>>>> --- a/drivers/media/platform/atmel/atmel-isc-scaler.c
>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-scaler.c
>>>>>> @@ -173,6 +173,10 @@ static const struct v4l2_subdev_pad_ops isc_scaler_pad_ops = {
>>>>>>         .init_cfg = isc_scaler_init_cfg,
>>>>>>    };
>>>>>>
>>>>>> +static const struct media_entity_operations isc_scaler_entity_ops = {
>>>>>> +     .link_validate = v4l2_subdev_link_validate,
>>>>>> +};
>>>>>> +
>>>>>>    static const struct v4l2_subdev_ops xisc_scaler_subdev_ops = {
>>>>>>         .pad = &isc_scaler_pad_ops,
>>>>>>    };
>>>>>> @@ -190,6 +194,7 @@ int isc_scaler_init(struct isc_device *isc)
>>>>>>
>>>>>>         isc->scaler_sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
>>>>>>         isc->scaler_sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_SCALER;
>>>>>> +     isc->scaler_sd.entity.ops = &isc_scaler_entity_ops;
>>>>>>         isc->scaler_pads[ISC_SCALER_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
>>>>>>         isc->scaler_pads[ISC_SCALER_PAD_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
>>>>>>
>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
>>>>>> index f98f25a55e73..5b0100c8c245 100644
>>>>>> --- a/drivers/media/platform/atmel/atmel-isc.h
>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc.h
>>>>>> @@ -63,15 +63,16 @@ struct isc_subdev_entity {
>>>>>>     * @cfa_baycfg:              If this format is RAW BAYER, indicate the type of bayer.
>>>>>>                         this is either BGBG, RGRG, etc.
>>>>>>     * @pfe_cfg0_bps:    Number of hardware data lines connected to the ISC
>>>>>> + * @raw:             If the format is raw bayer.
>>>>>>     */
>>>>>>
>>>>>>    struct isc_format {
>>>>>>         u32     fourcc;
>>>>>>         u32     mbus_code;
>>>>>>         u32     cfa_baycfg;
>>>>>> -
>>>>>> -     bool    sd_support;
>>>>>>         u32     pfe_cfg0_bps;
>>>>>> +
>>>>>> +     bool    raw;
>>>>>>    };
>>>>>>
>>>>>>    /* Pipeline bitmap */
>>>>>> @@ -216,8 +217,7 @@ enum isc_scaler_pads {
>>>>>>     * @comp:            completion reference that signals frame completion
>>>>>>     *
>>>>>>     * @fmt:             current v42l format
>>>>>> - * @user_formats:    list of formats that are supported and agreed with sd
>>>>>> - * @num_user_formats:        how many formats are in user_formats
>>>>>> + * @try_fmt:         current v4l2 try format
>>>>>>     *
>>>>>>     * @config:          current ISC format configuration
>>>>>>     * @try_config:              the current ISC try format , not yet activated
>>>>>> @@ -272,6 +272,7 @@ enum isc_scaler_pads {
>>>>>>     * @formats_list_size:       size of formats_list array
>>>>>>     * @pads:            media controller pads for isc video entity
>>>>>>     * @mdev:            media device that is registered by the isc
>>>>>> + * @mpipe:           media device pipeline used by the isc
>>>>>>     * @remote_pad:              remote pad on the connected subdevice
>>>>>>     * @scaler_sd:               subdevice for the scaler that isc registers
>>>>>>     * @scaler_pads:     media controller pads for the scaler subdevice
>>>>>> @@ -298,8 +299,7 @@ struct isc_device {
>>>>>>         struct completion       comp;
>>>>>>
>>>>>>         struct v4l2_format      fmt;
>>>>>> -     struct isc_format       **user_formats;
>>>>>> -     unsigned int            num_user_formats;
>>>>>> +     struct v4l2_format      try_fmt;
>>>>>>
>>>>>>         struct fmt_config       config;
>>>>>>         struct fmt_config       try_config;
>>>>>> @@ -369,6 +369,7 @@ struct isc_device {
>>>>>>         struct {
>>>>>>                 struct media_pad                pads[ISC_PADS_NUM];
>>>>>>                 struct media_device             mdev;
>>>>>> +             struct media_pipeline           mpipe;
>>>>>>
>>>>>>                 u32                             remote_pad;
>>>>>>         };
>>>>>> diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>>>>> index d96ee3373889..2a651e237193 100644
>>>>>> --- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>>>>> +++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
>>>>>> @@ -80,20 +80,40 @@ static const struct isc_format sama5d2_controller_formats[] = {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_Y10,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SBGGR8,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SGBRG8,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SGRBG8,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SRGGB8,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SBGGR10,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SGBRG10,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SGRBG10,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SRGGB10,
>>>>>> +             .raw            = true,
>>>>>> +     }, {
>>>>>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
>>>>>> +             .raw            = true,
>>>>>> +     }, {
>>>>>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
>>>>>> +             .raw            = true,
>>>>>> +     }, {
>>>>>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
>>>>>> +             .raw            = true,
>>>>>> +     }, {
>>>>>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
>>>>>> +             .raw            = true,
>>>>>>         },
>>>>>>    };
>>>>>>
>>>>>> diff --git a/drivers/media/platform/atmel/atmel-sama7g5-isc.c b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>>>>> index e07ae188c15f..a0d60cfdba7b 100644
>>>>>> --- a/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>>>>> +++ b/drivers/media/platform/atmel/atmel-sama7g5-isc.c
>>>>>> @@ -89,20 +89,40 @@ static const struct isc_format sama7g5_controller_formats[] = {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_Y16,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SBGGR8,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SGBRG8,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SGRBG8,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SRGGB8,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SBGGR10,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SGBRG10,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SGRBG10,
>>>>>> +             .raw            = true,
>>>>>>         }, {
>>>>>>                 .fourcc         = V4L2_PIX_FMT_SRGGB10,
>>>>>> +             .raw            = true,
>>>>>> +     }, {
>>>>>> +             .fourcc         = V4L2_PIX_FMT_SBGGR12,
>>>>>> +             .raw            = true,
>>>>>> +     }, {
>>>>>> +             .fourcc         = V4L2_PIX_FMT_SGBRG12,
>>>>>> +             .raw            = true,
>>>>>> +     }, {
>>>>>> +             .fourcc         = V4L2_PIX_FMT_SGRBG12,
>>>>>> +             .raw            = true,
>>>>>> +     }, {
>>>>>> +             .fourcc         = V4L2_PIX_FMT_SRGGB12,
>>>>>> +             .raw            = true,
>>>>>>         },
>>>>>>    };
>>>>>>
>>>>>
>>>>
>>>
>

On 29/04/2022 12:07, Laurent Pinchart wrote:
> On Fri, Apr 29, 2022 at 11:58:48AM +0200, Jacopo Mondi wrote:
>> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
>>> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
>>>> On 4/29/22 11:17 AM, Hans Verkuil wrote:
>>>>> On 10/03/2022 10:51, Eugen Hristev wrote:
>>>>>> As a top MC video driver, the atmel-isc should not propagate the format to the
>>>>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
>>>>>> configured with a compatible format.
>>>>>> Removed the whole format finding logic, and reworked the format verification
>>>>>> at start_streaming time, such that the ISC will return an error if the subdevice
>>>>>> is not properly configured. To achieve this, media_pipeline_start
>>>>>> is called and a link_validate callback is created to check the formats.
>>>>>> With this being done, the module parameter 'sensor_preferred' makes no sense
>>>>>> anymore. The ISC should not decide which format the sensor is using. The
>>>>>> ISC should only cope with the situation and inform userspace if the streaming
>>>>>> is possible in the current configuration.
>>>>>> The redesign of the format propagation has also risen the question of the
>>>>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
>>>>>> should only return the formats that are supported for this mbus_code.
>>>>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
>>>>>> With this rework, the dynamic list of user formats is removed. It makes no
>>>>>> more sense to identify at complete time which formats the sensor could emit,
>>>>>> and add those into a separate dynamic list.
>>>>>> The ISC will start with a simple preconfigured default format, and at
>>>>>> link validate time, decide whether it can use the format that is configured
>>>>>> on the sink or not.
>>>>>>
>>>>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>>>>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>>>>>> ---
>>>>>> Changes in v9:
>>>>>> - isc_link_validate now static
>>>>>>
>>>>>> Changes in v7:
>>>>>> - minor typos as suggested by Jacopo
>>>>>> - small changes, reduce some indentation, modified an index, as suggested by
>>>>>> Jacopo
>>>>>>
>>>>>> Changes in v6:
>>>>>> - reworked a bit enum_fmt as suggested by Jacopo
>>>>>>
>>>>>> Changes in v5:
>>>>>> - removed user_formats dynamic list as it is now pointless
>>>>>> - greatly simplified the enum_fmt function
>>>>>> - removed some init code that was useless now
>>>>>>
>>>>>> Changes in v4:
>>>>>> - moved validation code into link_validate and used media_pipeline_start
>>>>>> - merged this patch with the enum_fmt patch which was previously in v3 of
>>>>>> the series
>>>>>>
>>>>>> Changes in v3:
>>>>>> - clamp to maximum resolution once the frame size from the subdev is found
>>>>>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>>>>>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>>>>>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>>>>>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>>>>>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>>>>>>   5 files changed, 236 insertions(+), 234 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>> index ee1dda6707a0..fe2c0af58060 100644
>>>>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>> @@ -36,11 +36,6 @@ static unsigned int debug;
>>>>>>   module_param(debug, int, 0644);
>>>>>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
>>>>>>
>>>>>> -static unsigned int sensor_preferred = 1;
>>>>>> -module_param(sensor_preferred, uint, 0644);
>>>>>> -MODULE_PARM_DESC(sensor_preferred,
>>>>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>>>>>> -
>>>>>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
>>>>>>        (((mbus_code) & 0xf000) == 0x3000)
>>>>>>
>>>>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>>>>        unsigned long flags;
>>>>>>        int ret;
>>>>>>
>>>>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
>>>>>
>>>>> The pipeline validation is done in start_streaming, but I don't think that
>>>>> is the best place: if STREAMON is called before buffers are queued, then
>>>>> an invalid pipeline isn't discovered until enough buffers are queued to
>>>>> kick off start_streaming.
>>>>>
>>>>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
>>>>>
>>>>> I think that is the correct time to do this.
>>>>
>>>> Hello Hans,
>>>>
>>>> Initially (v2, v3) I had this in streamon(). The problem that I faced at
>>>> that time was that streamoff was never called, so I could not call
>>>> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
>>>> (see change log for v4) , and I did not face any more problems.
>>
>> Yes indeed, seems I suggested to use media_pipeline_handler in a
>> comment on your v3
>>
>> "at s_stream time your top driver calls media_pipeline_start()"
>>
>> sorry about that, I should have looked around a bit more carefully and
>> notice most drivers do so at vb2 streamon
>>
>> However I don't see media_pipeline_start being called at all in v3 of
>> the patch
>>
>>> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
>>> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
>>> isn't called), exynos4-is does the same, but it also checks the streaming state in
>>> the release() fop callback, so that would fix this problem. And vimc does this
>>> in stop_streaming.
>>>
>>> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
>>> to be called.
>>
>> Are you suggesting to have vb2 to call media_pipeline_start() or is it
>> more complex than this ?
> 
> I think Hans meant adding a .validate() operation to vb2.
> 
> vb2 is already quite complex, I don't think adding more features is a
> good idea. I'd rather have vb2 focus on buffer management only
> (.start_streaming() and .stop_streaming() shouldn't have been in there
> in my opinion), and handle validation in the .streamon() handler. I'd
> expect most drivers that deal with media pipelines to do more work in
> .streamon() anyway.

I disagree with that :-)

It's vb2 that keeps track of the streaming state and when what actions
need to be taken. Drivers really shouldn't need to care about the ioctls
themselves, and just implement the relevant vb2 callbacks. Relying on
drivers to handle any of the streaming ioctls is asking for problems,
as this shows: most drivers implement this wrong today.

The vb2 framework knows when e.g. the pipeline needs to be started or
stopped, and can do this at the best time, without drivers needing to
keep track of when streamon/off/release is called. Keep that logic in
vb2.

Regards,

	Hans

On Fri, Apr 29, 2022 at 12:13:46PM +0200, Hans Verkuil wrote:
> On 29/04/2022 12:07, Laurent Pinchart wrote:
> > On Fri, Apr 29, 2022 at 11:58:48AM +0200, Jacopo Mondi wrote:
> >> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
> >>> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
> >>>> On 4/29/22 11:17 AM, Hans Verkuil wrote:
> >>>>> On 10/03/2022 10:51, Eugen Hristev wrote:
> >>>>>> As a top MC video driver, the atmel-isc should not propagate the format to the
> >>>>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
> >>>>>> configured with a compatible format.
> >>>>>> Removed the whole format finding logic, and reworked the format verification
> >>>>>> at start_streaming time, such that the ISC will return an error if the subdevice
> >>>>>> is not properly configured. To achieve this, media_pipeline_start
> >>>>>> is called and a link_validate callback is created to check the formats.
> >>>>>> With this being done, the module parameter 'sensor_preferred' makes no sense
> >>>>>> anymore. The ISC should not decide which format the sensor is using. The
> >>>>>> ISC should only cope with the situation and inform userspace if the streaming
> >>>>>> is possible in the current configuration.
> >>>>>> The redesign of the format propagation has also risen the question of the
> >>>>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
> >>>>>> should only return the formats that are supported for this mbus_code.
> >>>>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
> >>>>>> With this rework, the dynamic list of user formats is removed. It makes no
> >>>>>> more sense to identify at complete time which formats the sensor could emit,
> >>>>>> and add those into a separate dynamic list.
> >>>>>> The ISC will start with a simple preconfigured default format, and at
> >>>>>> link validate time, decide whether it can use the format that is configured
> >>>>>> on the sink or not.
> >>>>>>
> >>>>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> >>>>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> >>>>>> ---
> >>>>>> Changes in v9:
> >>>>>> - isc_link_validate now static
> >>>>>>
> >>>>>> Changes in v7:
> >>>>>> - minor typos as suggested by Jacopo
> >>>>>> - small changes, reduce some indentation, modified an index, as suggested by
> >>>>>> Jacopo
> >>>>>>
> >>>>>> Changes in v6:
> >>>>>> - reworked a bit enum_fmt as suggested by Jacopo
> >>>>>>
> >>>>>> Changes in v5:
> >>>>>> - removed user_formats dynamic list as it is now pointless
> >>>>>> - greatly simplified the enum_fmt function
> >>>>>> - removed some init code that was useless now
> >>>>>>
> >>>>>> Changes in v4:
> >>>>>> - moved validation code into link_validate and used media_pipeline_start
> >>>>>> - merged this patch with the enum_fmt patch which was previously in v3 of
> >>>>>> the series
> >>>>>>
> >>>>>> Changes in v3:
> >>>>>> - clamp to maximum resolution once the frame size from the subdev is found
> >>>>>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
> >>>>>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
> >>>>>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
> >>>>>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
> >>>>>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
> >>>>>>   5 files changed, 236 insertions(+), 234 deletions(-)
> >>>>>>
> >>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
> >>>>>> index ee1dda6707a0..fe2c0af58060 100644
> >>>>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
> >>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
> >>>>>> @@ -36,11 +36,6 @@ static unsigned int debug;
> >>>>>>   module_param(debug, int, 0644);
> >>>>>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
> >>>>>>
> >>>>>> -static unsigned int sensor_preferred = 1;
> >>>>>> -module_param(sensor_preferred, uint, 0644);
> >>>>>> -MODULE_PARM_DESC(sensor_preferred,
> >>>>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
> >>>>>> -
> >>>>>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
> >>>>>>        (((mbus_code) & 0xf000) == 0x3000)
> >>>>>>
> >>>>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
> >>>>>>        unsigned long flags;
> >>>>>>        int ret;
> >>>>>>
> >>>>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
> >>>>>
> >>>>> The pipeline validation is done in start_streaming, but I don't think that
> >>>>> is the best place: if STREAMON is called before buffers are queued, then
> >>>>> an invalid pipeline isn't discovered until enough buffers are queued to
> >>>>> kick off start_streaming.
> >>>>>
> >>>>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
> >>>>>
> >>>>> I think that is the correct time to do this.
> >>>>
> >>>> Hello Hans,
> >>>>
> >>>> Initially (v2, v3) I had this in streamon(). The problem that I faced at
> >>>> that time was that streamoff was never called, so I could not call
> >>>> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
> >>>> (see change log for v4) , and I did not face any more problems.
> >>
> >> Yes indeed, seems I suggested to use media_pipeline_handler in a
> >> comment on your v3
> >>
> >> "at s_stream time your top driver calls media_pipeline_start()"
> >>
> >> sorry about that, I should have looked around a bit more carefully and
> >> notice most drivers do so at vb2 streamon
> >>
> >> However I don't see media_pipeline_start being called at all in v3 of
> >> the patch
> >>
> >>> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
> >>> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
> >>> isn't called), exynos4-is does the same, but it also checks the streaming state in
> >>> the release() fop callback, so that would fix this problem. And vimc does this
> >>> in stop_streaming.
> >>>
> >>> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
> >>> to be called.
> >>
> >> Are you suggesting to have vb2 to call media_pipeline_start() or is it
> >> more complex than this ?
> > 
> > I think Hans meant adding a .validate() operation to vb2.
> > 
> > vb2 is already quite complex, I don't think adding more features is a
> > good idea. I'd rather have vb2 focus on buffer management only
> > (.start_streaming() and .stop_streaming() shouldn't have been in there
> > in my opinion), and handle validation in the .streamon() handler. I'd
> > expect most drivers that deal with media pipelines to do more work in
> > .streamon() anyway.
> 
> I disagree with that :-)
> 
> It's vb2 that keeps track of the streaming state and when what actions
> need to be taken. Drivers really shouldn't need to care about the ioctls
> themselves, and just implement the relevant vb2 callbacks. Relying on
> drivers to handle any of the streaming ioctls is asking for problems,
> as this shows: most drivers implement this wrong today.
> 
> The vb2 framework knows when e.g. the pipeline needs to be started or
> stopped, and can do this at the best time, without drivers needing to
> keep track of when streamon/off/release is called. Keep that logic in
> vb2.

Pipeline management and buffer management are two different issues.
Don't forget about devices that have multiple video nodes, part of the
same pipeline (possibly a combination of output and capture nodes, or
all of the same type). Forcing drivers to go through vb2 operations to
handle the pipeline will be messy, will result in more bloat in vb2, and
make the result more bug-prone and harder to maintain.

If pipeline management is too complex, let's simplify it, new helpers
can make sense, but not through vb2.

On 29/04/2022 12:20, Laurent Pinchart wrote:
> On Fri, Apr 29, 2022 at 12:13:46PM +0200, Hans Verkuil wrote:
>> On 29/04/2022 12:07, Laurent Pinchart wrote:
>>> On Fri, Apr 29, 2022 at 11:58:48AM +0200, Jacopo Mondi wrote:
>>>> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
>>>>> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
>>>>>> On 4/29/22 11:17 AM, Hans Verkuil wrote:
>>>>>>> On 10/03/2022 10:51, Eugen Hristev wrote:
>>>>>>>> As a top MC video driver, the atmel-isc should not propagate the format to the
>>>>>>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
>>>>>>>> configured with a compatible format.
>>>>>>>> Removed the whole format finding logic, and reworked the format verification
>>>>>>>> at start_streaming time, such that the ISC will return an error if the subdevice
>>>>>>>> is not properly configured. To achieve this, media_pipeline_start
>>>>>>>> is called and a link_validate callback is created to check the formats.
>>>>>>>> With this being done, the module parameter 'sensor_preferred' makes no sense
>>>>>>>> anymore. The ISC should not decide which format the sensor is using. The
>>>>>>>> ISC should only cope with the situation and inform userspace if the streaming
>>>>>>>> is possible in the current configuration.
>>>>>>>> The redesign of the format propagation has also risen the question of the
>>>>>>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
>>>>>>>> should only return the formats that are supported for this mbus_code.
>>>>>>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
>>>>>>>> With this rework, the dynamic list of user formats is removed. It makes no
>>>>>>>> more sense to identify at complete time which formats the sensor could emit,
>>>>>>>> and add those into a separate dynamic list.
>>>>>>>> The ISC will start with a simple preconfigured default format, and at
>>>>>>>> link validate time, decide whether it can use the format that is configured
>>>>>>>> on the sink or not.
>>>>>>>>
>>>>>>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>>>>>>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>>>>>>>> ---
>>>>>>>> Changes in v9:
>>>>>>>> - isc_link_validate now static
>>>>>>>>
>>>>>>>> Changes in v7:
>>>>>>>> - minor typos as suggested by Jacopo
>>>>>>>> - small changes, reduce some indentation, modified an index, as suggested by
>>>>>>>> Jacopo
>>>>>>>>
>>>>>>>> Changes in v6:
>>>>>>>> - reworked a bit enum_fmt as suggested by Jacopo
>>>>>>>>
>>>>>>>> Changes in v5:
>>>>>>>> - removed user_formats dynamic list as it is now pointless
>>>>>>>> - greatly simplified the enum_fmt function
>>>>>>>> - removed some init code that was useless now
>>>>>>>>
>>>>>>>> Changes in v4:
>>>>>>>> - moved validation code into link_validate and used media_pipeline_start
>>>>>>>> - merged this patch with the enum_fmt patch which was previously in v3 of
>>>>>>>> the series
>>>>>>>>
>>>>>>>> Changes in v3:
>>>>>>>> - clamp to maximum resolution once the frame size from the subdev is found
>>>>>>>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>>>>>>>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>>>>>>>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>>>>>>>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>>>>>>>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>>>>>>>>   5 files changed, 236 insertions(+), 234 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>> index ee1dda6707a0..fe2c0af58060 100644
>>>>>>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>> @@ -36,11 +36,6 @@ static unsigned int debug;
>>>>>>>>   module_param(debug, int, 0644);
>>>>>>>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
>>>>>>>>
>>>>>>>> -static unsigned int sensor_preferred = 1;
>>>>>>>> -module_param(sensor_preferred, uint, 0644);
>>>>>>>> -MODULE_PARM_DESC(sensor_preferred,
>>>>>>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>>>>>>>> -
>>>>>>>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
>>>>>>>>        (((mbus_code) & 0xf000) == 0x3000)
>>>>>>>>
>>>>>>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>>>>>>        unsigned long flags;
>>>>>>>>        int ret;
>>>>>>>>
>>>>>>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
>>>>>>>
>>>>>>> The pipeline validation is done in start_streaming, but I don't think that
>>>>>>> is the best place: if STREAMON is called before buffers are queued, then
>>>>>>> an invalid pipeline isn't discovered until enough buffers are queued to
>>>>>>> kick off start_streaming.
>>>>>>>
>>>>>>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
>>>>>>>
>>>>>>> I think that is the correct time to do this.
>>>>>>
>>>>>> Hello Hans,
>>>>>>
>>>>>> Initially (v2, v3) I had this in streamon(). The problem that I faced at
>>>>>> that time was that streamoff was never called, so I could not call
>>>>>> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
>>>>>> (see change log for v4) , and I did not face any more problems.
>>>>
>>>> Yes indeed, seems I suggested to use media_pipeline_handler in a
>>>> comment on your v3
>>>>
>>>> "at s_stream time your top driver calls media_pipeline_start()"
>>>>
>>>> sorry about that, I should have looked around a bit more carefully and
>>>> notice most drivers do so at vb2 streamon
>>>>
>>>> However I don't see media_pipeline_start being called at all in v3 of
>>>> the patch
>>>>
>>>>> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
>>>>> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
>>>>> isn't called), exynos4-is does the same, but it also checks the streaming state in
>>>>> the release() fop callback, so that would fix this problem. And vimc does this
>>>>> in stop_streaming.
>>>>>
>>>>> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
>>>>> to be called.
>>>>
>>>> Are you suggesting to have vb2 to call media_pipeline_start() or is it
>>>> more complex than this ?
>>>
>>> I think Hans meant adding a .validate() operation to vb2.
>>>
>>> vb2 is already quite complex, I don't think adding more features is a
>>> good idea. I'd rather have vb2 focus on buffer management only
>>> (.start_streaming() and .stop_streaming() shouldn't have been in there
>>> in my opinion), and handle validation in the .streamon() handler. I'd
>>> expect most drivers that deal with media pipelines to do more work in
>>> .streamon() anyway.
>>
>> I disagree with that :-)
>>
>> It's vb2 that keeps track of the streaming state and when what actions
>> need to be taken. Drivers really shouldn't need to care about the ioctls
>> themselves, and just implement the relevant vb2 callbacks. Relying on
>> drivers to handle any of the streaming ioctls is asking for problems,
>> as this shows: most drivers implement this wrong today.
>>
>> The vb2 framework knows when e.g. the pipeline needs to be started or
>> stopped, and can do this at the best time, without drivers needing to
>> keep track of when streamon/off/release is called. Keep that logic in
>> vb2.
> 
> Pipeline management and buffer management are two different issues.
> Don't forget about devices that have multiple video nodes, part of the
> same pipeline (possibly a combination of output and capture nodes, or
> all of the same type). Forcing drivers to go through vb2 operations to
> handle the pipeline will be messy, will result in more bloat in vb2, and
> make the result more bug-prone and harder to maintain.
> 
> If pipeline management is too complex, let's simplify it, new helpers
> can make sense, but not through vb2.
> 

But it is vb2 that knows when streaming starts and stops. The driver just
needs to be informed (e.g. prepare_streaming and unprepare_streaming ops).

vb2 deals with buffer management and it keeps track of the streaming state
and makes the streaming state transitions. That *is* an integral part of
vb2. What is missing at the moment are callbacks done at streamon time and
when the streaming stops (streamoff, or close() when is_streaming is true).

If you want to implement stream validation in a driver, then there are a
lot of things you need to do:

- override streamon, make sure you call vb2_queue_is_busy(), validate the
  pipeline, then call vb2_streamon, if that fails, remember to stop the
  pipeline.

- override streamoff, make sure you call vb2_queue_is_busy(), stop the
  pipeline and call vb2_streamoff.

- in the release() function when the fh is closed, you have to check
  vb2_is_streaming(), check that you are the owner of the queue, and if true,
  stop the pipeline.

By moving this to vb2 ops all you need to implement are the prepare and
unprepare ops.

Esp. the release() implementation is tricky. I'm pretty sure that
drivers/media/platform/samsung/exynos4-is/fimc-lite.c is wrong, since it
should only call media_pipeline_stop() for the owner of the queue. Instead
it calls it for the last user of the queue.

I see that fimc_lite_streamoff() is wrong too: you can safely call
VIDIOC_STREAMOFF twice: the second streamoff just returns 0 without
doing anything. Instead media_pipeline_stop is called without testing if
the queue is streaming.

And yes, this is in part because V4L2 has quite some history and certainly
API choice were made in the past that we wouldn't make today. But vb2
shields you from that, and behaves much more like a proper state machine.

I know you prefer to give a lot more control to driver developers, but
in my experience very few developers can do things like this right. And
it is really hard as a reviewer to check if all the corner cases are handled
correctly in a driver. If vb2 is used, then I know things are called at the
right time, and that makes my life as reviewer so much easier.

There may still be a few drivers that really need to do this manually, and
that's OK, but a driver like the atmel-isc doesn't need that at all.

Regards,

	Hans

On Fri, Apr 29, 2022 at 01:17:27PM +0200, Hans Verkuil wrote:
> On 29/04/2022 12:20, Laurent Pinchart wrote:
> > On Fri, Apr 29, 2022 at 12:13:46PM +0200, Hans Verkuil wrote:
> >> On 29/04/2022 12:07, Laurent Pinchart wrote:
> >>> On Fri, Apr 29, 2022 at 11:58:48AM +0200, Jacopo Mondi wrote:
> >>>> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
> >>>>> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
> >>>>>> On 4/29/22 11:17 AM, Hans Verkuil wrote:
> >>>>>>> On 10/03/2022 10:51, Eugen Hristev wrote:
> >>>>>>>> As a top MC video driver, the atmel-isc should not propagate the format to the
> >>>>>>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
> >>>>>>>> configured with a compatible format.
> >>>>>>>> Removed the whole format finding logic, and reworked the format verification
> >>>>>>>> at start_streaming time, such that the ISC will return an error if the subdevice
> >>>>>>>> is not properly configured. To achieve this, media_pipeline_start
> >>>>>>>> is called and a link_validate callback is created to check the formats.
> >>>>>>>> With this being done, the module parameter 'sensor_preferred' makes no sense
> >>>>>>>> anymore. The ISC should not decide which format the sensor is using. The
> >>>>>>>> ISC should only cope with the situation and inform userspace if the streaming
> >>>>>>>> is possible in the current configuration.
> >>>>>>>> The redesign of the format propagation has also risen the question of the
> >>>>>>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
> >>>>>>>> should only return the formats that are supported for this mbus_code.
> >>>>>>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
> >>>>>>>> With this rework, the dynamic list of user formats is removed. It makes no
> >>>>>>>> more sense to identify at complete time which formats the sensor could emit,
> >>>>>>>> and add those into a separate dynamic list.
> >>>>>>>> The ISC will start with a simple preconfigured default format, and at
> >>>>>>>> link validate time, decide whether it can use the format that is configured
> >>>>>>>> on the sink or not.
> >>>>>>>>
> >>>>>>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> >>>>>>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
> >>>>>>>> ---
> >>>>>>>> Changes in v9:
> >>>>>>>> - isc_link_validate now static
> >>>>>>>>
> >>>>>>>> Changes in v7:
> >>>>>>>> - minor typos as suggested by Jacopo
> >>>>>>>> - small changes, reduce some indentation, modified an index, as suggested by
> >>>>>>>> Jacopo
> >>>>>>>>
> >>>>>>>> Changes in v6:
> >>>>>>>> - reworked a bit enum_fmt as suggested by Jacopo
> >>>>>>>>
> >>>>>>>> Changes in v5:
> >>>>>>>> - removed user_formats dynamic list as it is now pointless
> >>>>>>>> - greatly simplified the enum_fmt function
> >>>>>>>> - removed some init code that was useless now
> >>>>>>>>
> >>>>>>>> Changes in v4:
> >>>>>>>> - moved validation code into link_validate and used media_pipeline_start
> >>>>>>>> - merged this patch with the enum_fmt patch which was previously in v3 of
> >>>>>>>> the series
> >>>>>>>>
> >>>>>>>> Changes in v3:
> >>>>>>>> - clamp to maximum resolution once the frame size from the subdev is found
> >>>>>>>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
> >>>>>>>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
> >>>>>>>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
> >>>>>>>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
> >>>>>>>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
> >>>>>>>>   5 files changed, 236 insertions(+), 234 deletions(-)
> >>>>>>>>
> >>>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
> >>>>>>>> index ee1dda6707a0..fe2c0af58060 100644
> >>>>>>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
> >>>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
> >>>>>>>> @@ -36,11 +36,6 @@ static unsigned int debug;
> >>>>>>>>   module_param(debug, int, 0644);
> >>>>>>>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
> >>>>>>>>
> >>>>>>>> -static unsigned int sensor_preferred = 1;
> >>>>>>>> -module_param(sensor_preferred, uint, 0644);
> >>>>>>>> -MODULE_PARM_DESC(sensor_preferred,
> >>>>>>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
> >>>>>>>> -
> >>>>>>>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
> >>>>>>>>        (((mbus_code) & 0xf000) == 0x3000)
> >>>>>>>>
> >>>>>>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
> >>>>>>>>        unsigned long flags;
> >>>>>>>>        int ret;
> >>>>>>>>
> >>>>>>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
> >>>>>>>
> >>>>>>> The pipeline validation is done in start_streaming, but I don't think that
> >>>>>>> is the best place: if STREAMON is called before buffers are queued, then
> >>>>>>> an invalid pipeline isn't discovered until enough buffers are queued to
> >>>>>>> kick off start_streaming.
> >>>>>>>
> >>>>>>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
> >>>>>>>
> >>>>>>> I think that is the correct time to do this.
> >>>>>>
> >>>>>> Hello Hans,
> >>>>>>
> >>>>>> Initially (v2, v3) I had this in streamon(). The problem that I faced at
> >>>>>> that time was that streamoff was never called, so I could not call
> >>>>>> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
> >>>>>> (see change log for v4) , and I did not face any more problems.
> >>>>
> >>>> Yes indeed, seems I suggested to use media_pipeline_handler in a
> >>>> comment on your v3
> >>>>
> >>>> "at s_stream time your top driver calls media_pipeline_start()"
> >>>>
> >>>> sorry about that, I should have looked around a bit more carefully and
> >>>> notice most drivers do so at vb2 streamon
> >>>>
> >>>> However I don't see media_pipeline_start being called at all in v3 of
> >>>> the patch
> >>>>
> >>>>> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
> >>>>> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
> >>>>> isn't called), exynos4-is does the same, but it also checks the streaming state in
> >>>>> the release() fop callback, so that would fix this problem. And vimc does this
> >>>>> in stop_streaming.
> >>>>>
> >>>>> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
> >>>>> to be called.
> >>>>
> >>>> Are you suggesting to have vb2 to call media_pipeline_start() or is it
> >>>> more complex than this ?
> >>>
> >>> I think Hans meant adding a .validate() operation to vb2.
> >>>
> >>> vb2 is already quite complex, I don't think adding more features is a
> >>> good idea. I'd rather have vb2 focus on buffer management only
> >>> (.start_streaming() and .stop_streaming() shouldn't have been in there
> >>> in my opinion), and handle validation in the .streamon() handler. I'd
> >>> expect most drivers that deal with media pipelines to do more work in
> >>> .streamon() anyway.
> >>
> >> I disagree with that :-)
> >>
> >> It's vb2 that keeps track of the streaming state and when what actions
> >> need to be taken. Drivers really shouldn't need to care about the ioctls
> >> themselves, and just implement the relevant vb2 callbacks. Relying on
> >> drivers to handle any of the streaming ioctls is asking for problems,
> >> as this shows: most drivers implement this wrong today.
> >>
> >> The vb2 framework knows when e.g. the pipeline needs to be started or
> >> stopped, and can do this at the best time, without drivers needing to
> >> keep track of when streamon/off/release is called. Keep that logic in
> >> vb2.
> > 
> > Pipeline management and buffer management are two different issues.
> > Don't forget about devices that have multiple video nodes, part of the
> > same pipeline (possibly a combination of output and capture nodes, or
> > all of the same type). Forcing drivers to go through vb2 operations to
> > handle the pipeline will be messy, will result in more bloat in vb2, and
> > make the result more bug-prone and harder to maintain.
> > 
> > If pipeline management is too complex, let's simplify it, new helpers
> > can make sense, but not through vb2.
> > 
> 
> But it is vb2 that knows when streaming starts and stops.

That's right, but pipeline start (which includes validation and resource
reservation) needs to be performed synchronously with VIDIOC_STREAMON.
The streaming state managed by vb2 is not relevant,
media_pipeline_start() must not be delayed the same way
.start_streaming() is.

> The driver just
> needs to be informed (e.g. prepare_streaming and unprepare_streaming ops).
> 
> vb2 deals with buffer management and it keeps track of the streaming state
> and makes the streaming state transitions. That *is* an integral part of
> vb2. What is missing at the moment are callbacks done at streamon time and
> when the streaming stops (streamoff, or close() when is_streaming is true).
> 
> If you want to implement stream validation in a driver, then there are a
> lot of things you need to do:
> 
> - override streamon, make sure you call vb2_queue_is_busy(), validate the
>   pipeline, then call vb2_streamon, if that fails, remember to stop the
>   pipeline.
> 
> - override streamoff, make sure you call vb2_queue_is_busy(), stop the
>   pipeline and call vb2_streamoff.
> 
> - in the release() function when the fh is closed, you have to check
>   vb2_is_streaming(), check that you are the owner of the queue, and if true,
>   stop the pipeline.

I'm not opposed to helper functions to implement that, they can bundle
vb2 calls and pipeline management.

> By moving this to vb2 ops all you need to implement are the prepare and
> unprepare ops.
> 
> Esp. the release() implementation is tricky. I'm pretty sure that
> drivers/media/platform/samsung/exynos4-is/fimc-lite.c is wrong, since it
> should only call media_pipeline_stop() for the owner of the queue. Instead
> it calls it for the last user of the queue.
> 
> I see that fimc_lite_streamoff() is wrong too: you can safely call
> VIDIOC_STREAMOFF twice: the second streamoff just returns 0 without
> doing anything. Instead media_pipeline_stop is called without testing if
> the queue is streaming.
> 
> And yes, this is in part because V4L2 has quite some history and certainly
> API choice were made in the past that we wouldn't make today. But vb2
> shields you from that, and behaves much more like a proper state machine.
> 
> I know you prefer to give a lot more control to driver developers, but
> in my experience very few developers can do things like this right. And
> it is really hard as a reviewer to check if all the corner cases are handled
> correctly in a driver. If vb2 is used, then I know things are called at the
> right time, and that makes my life as reviewer so much easier.

It's not just about giving more control to drivers, it's about
organizing the software layers in a way that keeps them maintainable,
with layered abstractions and not midlayers.

We are extensively reworking the media pipeline management as part of
the stream series, and there will be more work on top of that that will
make even more fundamental changes. I would like to at least postpone
any work on vb2 until then, to be able to evaluate the impact.

> There may still be a few drivers that really need to do this manually, and
> that's OK, but a driver like the atmel-isc doesn't need that at all.

On 29/04/2022 14:02, Laurent Pinchart wrote:
> On Fri, Apr 29, 2022 at 01:17:27PM +0200, Hans Verkuil wrote:
>> On 29/04/2022 12:20, Laurent Pinchart wrote:
>>> On Fri, Apr 29, 2022 at 12:13:46PM +0200, Hans Verkuil wrote:
>>>> On 29/04/2022 12:07, Laurent Pinchart wrote:
>>>>> On Fri, Apr 29, 2022 at 11:58:48AM +0200, Jacopo Mondi wrote:
>>>>>> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
>>>>>>> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
>>>>>>>> On 4/29/22 11:17 AM, Hans Verkuil wrote:
>>>>>>>>> On 10/03/2022 10:51, Eugen Hristev wrote:
>>>>>>>>>> As a top MC video driver, the atmel-isc should not propagate the format to the
>>>>>>>>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
>>>>>>>>>> configured with a compatible format.
>>>>>>>>>> Removed the whole format finding logic, and reworked the format verification
>>>>>>>>>> at start_streaming time, such that the ISC will return an error if the subdevice
>>>>>>>>>> is not properly configured. To achieve this, media_pipeline_start
>>>>>>>>>> is called and a link_validate callback is created to check the formats.
>>>>>>>>>> With this being done, the module parameter 'sensor_preferred' makes no sense
>>>>>>>>>> anymore. The ISC should not decide which format the sensor is using. The
>>>>>>>>>> ISC should only cope with the situation and inform userspace if the streaming
>>>>>>>>>> is possible in the current configuration.
>>>>>>>>>> The redesign of the format propagation has also risen the question of the
>>>>>>>>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
>>>>>>>>>> should only return the formats that are supported for this mbus_code.
>>>>>>>>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
>>>>>>>>>> With this rework, the dynamic list of user formats is removed. It makes no
>>>>>>>>>> more sense to identify at complete time which formats the sensor could emit,
>>>>>>>>>> and add those into a separate dynamic list.
>>>>>>>>>> The ISC will start with a simple preconfigured default format, and at
>>>>>>>>>> link validate time, decide whether it can use the format that is configured
>>>>>>>>>> on the sink or not.
>>>>>>>>>>
>>>>>>>>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>>>>>>>>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>>>>>>>>>> ---
>>>>>>>>>> Changes in v9:
>>>>>>>>>> - isc_link_validate now static
>>>>>>>>>>
>>>>>>>>>> Changes in v7:
>>>>>>>>>> - minor typos as suggested by Jacopo
>>>>>>>>>> - small changes, reduce some indentation, modified an index, as suggested by
>>>>>>>>>> Jacopo
>>>>>>>>>>
>>>>>>>>>> Changes in v6:
>>>>>>>>>> - reworked a bit enum_fmt as suggested by Jacopo
>>>>>>>>>>
>>>>>>>>>> Changes in v5:
>>>>>>>>>> - removed user_formats dynamic list as it is now pointless
>>>>>>>>>> - greatly simplified the enum_fmt function
>>>>>>>>>> - removed some init code that was useless now
>>>>>>>>>>
>>>>>>>>>> Changes in v4:
>>>>>>>>>> - moved validation code into link_validate and used media_pipeline_start
>>>>>>>>>> - merged this patch with the enum_fmt patch which was previously in v3 of
>>>>>>>>>> the series
>>>>>>>>>>
>>>>>>>>>> Changes in v3:
>>>>>>>>>> - clamp to maximum resolution once the frame size from the subdev is found
>>>>>>>>>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>>>>>>>>>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>>>>>>>>>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>>>>>>>>>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>>>>>>>>>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>>>>>>>>>>   5 files changed, 236 insertions(+), 234 deletions(-)
>>>>>>>>>>
>>>>>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>>>> index ee1dda6707a0..fe2c0af58060 100644
>>>>>>>>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>>>> @@ -36,11 +36,6 @@ static unsigned int debug;
>>>>>>>>>>   module_param(debug, int, 0644);
>>>>>>>>>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
>>>>>>>>>>
>>>>>>>>>> -static unsigned int sensor_preferred = 1;
>>>>>>>>>> -module_param(sensor_preferred, uint, 0644);
>>>>>>>>>> -MODULE_PARM_DESC(sensor_preferred,
>>>>>>>>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>>>>>>>>>> -
>>>>>>>>>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
>>>>>>>>>>        (((mbus_code) & 0xf000) == 0x3000)
>>>>>>>>>>
>>>>>>>>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>>>>>>>>        unsigned long flags;
>>>>>>>>>>        int ret;
>>>>>>>>>>
>>>>>>>>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
>>>>>>>>>
>>>>>>>>> The pipeline validation is done in start_streaming, but I don't think that
>>>>>>>>> is the best place: if STREAMON is called before buffers are queued, then
>>>>>>>>> an invalid pipeline isn't discovered until enough buffers are queued to
>>>>>>>>> kick off start_streaming.
>>>>>>>>>
>>>>>>>>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
>>>>>>>>>
>>>>>>>>> I think that is the correct time to do this.
>>>>>>>>
>>>>>>>> Hello Hans,
>>>>>>>>
>>>>>>>> Initially (v2, v3) I had this in streamon(). The problem that I faced at
>>>>>>>> that time was that streamoff was never called, so I could not call
>>>>>>>> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
>>>>>>>> (see change log for v4) , and I did not face any more problems.
>>>>>>
>>>>>> Yes indeed, seems I suggested to use media_pipeline_handler in a
>>>>>> comment on your v3
>>>>>>
>>>>>> "at s_stream time your top driver calls media_pipeline_start()"
>>>>>>
>>>>>> sorry about that, I should have looked around a bit more carefully and
>>>>>> notice most drivers do so at vb2 streamon
>>>>>>
>>>>>> However I don't see media_pipeline_start being called at all in v3 of
>>>>>> the patch
>>>>>>
>>>>>>> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
>>>>>>> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
>>>>>>> isn't called), exynos4-is does the same, but it also checks the streaming state in
>>>>>>> the release() fop callback, so that would fix this problem. And vimc does this
>>>>>>> in stop_streaming.
>>>>>>>
>>>>>>> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
>>>>>>> to be called.
>>>>>>
>>>>>> Are you suggesting to have vb2 to call media_pipeline_start() or is it
>>>>>> more complex than this ?
>>>>>
>>>>> I think Hans meant adding a .validate() operation to vb2.
>>>>>
>>>>> vb2 is already quite complex, I don't think adding more features is a
>>>>> good idea. I'd rather have vb2 focus on buffer management only
>>>>> (.start_streaming() and .stop_streaming() shouldn't have been in there
>>>>> in my opinion), and handle validation in the .streamon() handler. I'd
>>>>> expect most drivers that deal with media pipelines to do more work in
>>>>> .streamon() anyway.
>>>>
>>>> I disagree with that :-)
>>>>
>>>> It's vb2 that keeps track of the streaming state and when what actions
>>>> need to be taken. Drivers really shouldn't need to care about the ioctls
>>>> themselves, and just implement the relevant vb2 callbacks. Relying on
>>>> drivers to handle any of the streaming ioctls is asking for problems,
>>>> as this shows: most drivers implement this wrong today.
>>>>
>>>> The vb2 framework knows when e.g. the pipeline needs to be started or
>>>> stopped, and can do this at the best time, without drivers needing to
>>>> keep track of when streamon/off/release is called. Keep that logic in
>>>> vb2.
>>>
>>> Pipeline management and buffer management are two different issues.
>>> Don't forget about devices that have multiple video nodes, part of the
>>> same pipeline (possibly a combination of output and capture nodes, or
>>> all of the same type). Forcing drivers to go through vb2 operations to
>>> handle the pipeline will be messy, will result in more bloat in vb2, and
>>> make the result more bug-prone and harder to maintain.
>>>
>>> If pipeline management is too complex, let's simplify it, new helpers
>>> can make sense, but not through vb2.
>>>
>>
>> But it is vb2 that knows when streaming starts and stops.
> 
> That's right, but pipeline start (which includes validation and resource
> reservation) needs to be performed synchronously with VIDIOC_STREAMON.
> The streaming state managed by vb2 is not relevant,
> media_pipeline_start() must not be delayed the same way
> .start_streaming() is.

It will be the first thing that vb2_streamon calls. This has nothing to do
with start_streaming: that's called when sufficient number of buffers are
queued up to be able to start the DMA. This proposed prepare_streaming op
will be called when VIDIOC_STREAMON is called.

> 
>> The driver just
>> needs to be informed (e.g. prepare_streaming and unprepare_streaming ops).
>>
>> vb2 deals with buffer management and it keeps track of the streaming state
>> and makes the streaming state transitions. That *is* an integral part of
>> vb2. What is missing at the moment are callbacks done at streamon time and
>> when the streaming stops (streamoff, or close() when is_streaming is true).
>>
>> If you want to implement stream validation in a driver, then there are a
>> lot of things you need to do:
>>
>> - override streamon, make sure you call vb2_queue_is_busy(), validate the
>>   pipeline, then call vb2_streamon, if that fails, remember to stop the
>>   pipeline.
>>
>> - override streamoff, make sure you call vb2_queue_is_busy(), stop the
>>   pipeline and call vb2_streamoff.
>>
>> - in the release() function when the fh is closed, you have to check
>>   vb2_is_streaming(), check that you are the owner of the queue, and if true,
>>   stop the pipeline.
> 
> I'm not opposed to helper functions to implement that, they can bundle
> vb2 calls and pipeline management.
> 
>> By moving this to vb2 ops all you need to implement are the prepare and
>> unprepare ops.
>>
>> Esp. the release() implementation is tricky. I'm pretty sure that
>> drivers/media/platform/samsung/exynos4-is/fimc-lite.c is wrong, since it
>> should only call media_pipeline_stop() for the owner of the queue. Instead
>> it calls it for the last user of the queue.
>>
>> I see that fimc_lite_streamoff() is wrong too: you can safely call
>> VIDIOC_STREAMOFF twice: the second streamoff just returns 0 without
>> doing anything. Instead media_pipeline_stop is called without testing if
>> the queue is streaming.
>>
>> And yes, this is in part because V4L2 has quite some history and certainly
>> API choice were made in the past that we wouldn't make today. But vb2
>> shields you from that, and behaves much more like a proper state machine.
>>
>> I know you prefer to give a lot more control to driver developers, but
>> in my experience very few developers can do things like this right. And
>> it is really hard as a reviewer to check if all the corner cases are handled
>> correctly in a driver. If vb2 is used, then I know things are called at the
>> right time, and that makes my life as reviewer so much easier.
> 
> It's not just about giving more control to drivers, it's about
> organizing the software layers in a way that keeps them maintainable,
> with layered abstractions and not midlayers.
> 
> We are extensively reworking the media pipeline management as part of
> the stream series, and there will be more work on top of that that will
> make even more fundamental changes. I would like to at least postpone
> any work on vb2 until then, to be able to evaluate the impact.

I'll make an RFC patch for vb2 so you have a better idea of what it does.

Regards,

	Hans

> 
>> There may still be a few drivers that really need to do this manually, and
>> that's OK, but a driver like the atmel-isc doesn't need that at all.
>

On 29/04/2022 14:38, Jacopo Mondi wrote:
> Hi
> 
> On Fri, Apr 29, 2022 at 03:28:11PM +0300, Laurent Pinchart wrote:
>> On Fri, Apr 29, 2022 at 02:23:45PM +0200, Hans Verkuil wrote:
>>> On 29/04/2022 14:02, Laurent Pinchart wrote:
>>>> On Fri, Apr 29, 2022 at 01:17:27PM +0200, Hans Verkuil wrote:
>>>>> On 29/04/2022 12:20, Laurent Pinchart wrote:
>>>>>> On Fri, Apr 29, 2022 at 12:13:46PM +0200, Hans Verkuil wrote:
>>>>>>> On 29/04/2022 12:07, Laurent Pinchart wrote:
>>>>>>>> On Fri, Apr 29, 2022 at 11:58:48AM +0200, Jacopo Mondi wrote:
>>>>>>>>> On Fri, Apr 29, 2022 at 10:43:09AM +0200, Hans Verkuil wrote:
>>>>>>>>>> On 29/04/2022 10:28, Eugen.Hristev@microchip.com wrote:
>>>>>>>>>>> On 4/29/22 11:17 AM, Hans Verkuil wrote:
>>>>>>>>>>>> On 10/03/2022 10:51, Eugen Hristev wrote:
>>>>>>>>>>>>> As a top MC video driver, the atmel-isc should not propagate the format to the
>>>>>>>>>>>>> subdevice, it should rather check at start_streaming() time if the subdev is properly
>>>>>>>>>>>>> configured with a compatible format.
>>>>>>>>>>>>> Removed the whole format finding logic, and reworked the format verification
>>>>>>>>>>>>> at start_streaming time, such that the ISC will return an error if the subdevice
>>>>>>>>>>>>> is not properly configured. To achieve this, media_pipeline_start
>>>>>>>>>>>>> is called and a link_validate callback is created to check the formats.
>>>>>>>>>>>>> With this being done, the module parameter 'sensor_preferred' makes no sense
>>>>>>>>>>>>> anymore. The ISC should not decide which format the sensor is using. The
>>>>>>>>>>>>> ISC should only cope with the situation and inform userspace if the streaming
>>>>>>>>>>>>> is possible in the current configuration.
>>>>>>>>>>>>> The redesign of the format propagation has also risen the question of the
>>>>>>>>>>>>> enumfmt callback. If enumfmt is called with an mbus_code, the enumfmt handler
>>>>>>>>>>>>> should only return the formats that are supported for this mbus_code.
>>>>>>>>>>>>> Otherwise, the enumfmt will report all the formats that the ISC could output.
>>>>>>>>>>>>> With this rework, the dynamic list of user formats is removed. It makes no
>>>>>>>>>>>>> more sense to identify at complete time which formats the sensor could emit,
>>>>>>>>>>>>> and add those into a separate dynamic list.
>>>>>>>>>>>>> The ISC will start with a simple preconfigured default format, and at
>>>>>>>>>>>>> link validate time, decide whether it can use the format that is configured
>>>>>>>>>>>>> on the sink or not.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>>>>>>>>>>>>> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
>>>>>>>>>>>>> ---
>>>>>>>>>>>>> Changes in v9:
>>>>>>>>>>>>> - isc_link_validate now static
>>>>>>>>>>>>>
>>>>>>>>>>>>> Changes in v7:
>>>>>>>>>>>>> - minor typos as suggested by Jacopo
>>>>>>>>>>>>> - small changes, reduce some indentation, modified an index, as suggested by
>>>>>>>>>>>>> Jacopo
>>>>>>>>>>>>>
>>>>>>>>>>>>> Changes in v6:
>>>>>>>>>>>>> - reworked a bit enum_fmt as suggested by Jacopo
>>>>>>>>>>>>>
>>>>>>>>>>>>> Changes in v5:
>>>>>>>>>>>>> - removed user_formats dynamic list as it is now pointless
>>>>>>>>>>>>> - greatly simplified the enum_fmt function
>>>>>>>>>>>>> - removed some init code that was useless now
>>>>>>>>>>>>>
>>>>>>>>>>>>> Changes in v4:
>>>>>>>>>>>>> - moved validation code into link_validate and used media_pipeline_start
>>>>>>>>>>>>> - merged this patch with the enum_fmt patch which was previously in v3 of
>>>>>>>>>>>>> the series
>>>>>>>>>>>>>
>>>>>>>>>>>>> Changes in v3:
>>>>>>>>>>>>> - clamp to maximum resolution once the frame size from the subdev is found
>>>>>>>>>>>>>   drivers/media/platform/atmel/atmel-isc-base.c | 412 ++++++++----------
>>>>>>>>>>>>>   .../media/platform/atmel/atmel-isc-scaler.c   |   5 +
>>>>>>>>>>>>>   drivers/media/platform/atmel/atmel-isc.h      |  13 +-
>>>>>>>>>>>>>   .../media/platform/atmel/atmel-sama5d2-isc.c  |  20 +
>>>>>>>>>>>>>   .../media/platform/atmel/atmel-sama7g5-isc.c  |  20 +
>>>>>>>>>>>>>   5 files changed, 236 insertions(+), 234 deletions(-)
>>>>>>>>>>>>>
>>>>>>>>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>>>>>>> index ee1dda6707a0..fe2c0af58060 100644
>>>>>>>>>>>>> --- a/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
>>>>>>>>>>>>> @@ -36,11 +36,6 @@ static unsigned int debug;
>>>>>>>>>>>>>   module_param(debug, int, 0644);
>>>>>>>>>>>>>   MODULE_PARM_DESC(debug, "debug level (0-2)");
>>>>>>>>>>>>>
>>>>>>>>>>>>> -static unsigned int sensor_preferred = 1;
>>>>>>>>>>>>> -module_param(sensor_preferred, uint, 0644);
>>>>>>>>>>>>> -MODULE_PARM_DESC(sensor_preferred,
>>>>>>>>>>>>> -              "Sensor is preferred to output the specified format (1-on 0-off), default 1");
>>>>>>>>>>>>> -
>>>>>>>>>>>>>   #define ISC_IS_FORMAT_RAW(mbus_code) \
>>>>>>>>>>>>>        (((mbus_code) & 0xf000) == 0x3000)
>>>>>>>>>>>>>
>>>>>>>>>>>>> @@ -337,6 +332,10 @@ static int isc_start_streaming(struct vb2_queue *vq, unsigned int count)
>>>>>>>>>>>>>        unsigned long flags;
>>>>>>>>>>>>>        int ret;
>>>>>>>>>>>>>
>>>>>>>>>>>>> +     ret = media_pipeline_start(&isc->video_dev.entity, &isc->mpipe);
>>>>>>>>>>>>
>>>>>>>>>>>> The pipeline validation is done in start_streaming, but I don't think that
>>>>>>>>>>>> is the best place: if STREAMON is called before buffers are queued, then
>>>>>>>>>>>> an invalid pipeline isn't discovered until enough buffers are queued to
>>>>>>>>>>>> kick off start_streaming.
>>>>>>>>>>>>
>>>>>>>>>>>> Drivers like vsp1, omap3isp and the samsung drivers all do this in streamon().
>>>>>>>>>>>>
>>>>>>>>>>>> I think that is the correct time to do this.
>>>>>>>>>>>
>>>>>>>>>>> Hello Hans,
>>>>>>>>>>>
>>>>>>>>>>> Initially (v2, v3) I had this in streamon(). The problem that I faced at
>>>>>>>>>>> that time was that streamoff was never called, so I could not call
>>>>>>>>>>> media_pipeline_stop(). Then Jacopo told me to move it to start_streaming
>>>>>>>>>>> (see change log for v4) , and I did not face any more problems.
>>>>>>>>>
>>>>>>>>> Yes indeed, seems I suggested to use media_pipeline_handler in a
>>>>>>>>> comment on your v3
>>>>>>>>>
>>>>>>>>> "at s_stream time your top driver calls media_pipeline_start()"
>>>>>>>>>
>>>>>>>>> sorry about that, I should have looked around a bit more carefully and
>>>>>>>>> notice most drivers do so at vb2 streamon
>>>>>>>>>
>>>>>>>>> However I don't see media_pipeline_start being called at all in v3 of
>>>>>>>>> the patch
>>>>>>>>>
>>>>>>>>>> It's a mess. Looking at some drivers I see that omap3isp calls media_pipeline_stop
>>>>>>>>>> in streamoff (so will have the same problem as you described if VIDIOC_STREAMOFF
>>>>>>>>>> isn't called), exynos4-is does the same, but it also checks the streaming state in
>>>>>>>>>> the release() fop callback, so that would fix this problem. And vimc does this
>>>>>>>>>> in stop_streaming.
>>>>>>>>>>
>>>>>>>>>> I'm in favor of fixing this in vb2, that framework knows exactly when this needs
>>>>>>>>>> to be called.
>>>>>>>>>
>>>>>>>>> Are you suggesting to have vb2 to call media_pipeline_start() or is it
>>>>>>>>> more complex than this ?
>>>>>>>>
>>>>>>>> I think Hans meant adding a .validate() operation to vb2.
>>>>>>>>
>>>>>>>> vb2 is already quite complex, I don't think adding more features is a
>>>>>>>> good idea. I'd rather have vb2 focus on buffer management only
>>>>>>>> (.start_streaming() and .stop_streaming() shouldn't have been in there
>>>>>>>> in my opinion), and handle validation in the .streamon() handler. I'd
>>>>>>>> expect most drivers that deal with media pipelines to do more work in
>>>>>>>> .streamon() anyway.
>>>>>>>
>>>>>>> I disagree with that :-)
>>>>>>>
>>>>>>> It's vb2 that keeps track of the streaming state and when what actions
>>>>>>> need to be taken. Drivers really shouldn't need to care about the ioctls
>>>>>>> themselves, and just implement the relevant vb2 callbacks. Relying on
>>>>>>> drivers to handle any of the streaming ioctls is asking for problems,
>>>>>>> as this shows: most drivers implement this wrong today.
>>>>>>>
>>>>>>> The vb2 framework knows when e.g. the pipeline needs to be started or
>>>>>>> stopped, and can do this at the best time, without drivers needing to
>>>>>>> keep track of when streamon/off/release is called. Keep that logic in
>>>>>>> vb2.
>>>>>>
>>>>>> Pipeline management and buffer management are two different issues.
>>>>>> Don't forget about devices that have multiple video nodes, part of the
>>>>>> same pipeline (possibly a combination of output and capture nodes, or
>>>>>> all of the same type). Forcing drivers to go through vb2 operations to
>>>>>> handle the pipeline will be messy, will result in more bloat in vb2, and
>>>>>> make the result more bug-prone and harder to maintain.
>>>>>>
>>>>>> If pipeline management is too complex, let's simplify it, new helpers
>>>>>> can make sense, but not through vb2.
>>>>>
>>>>> But it is vb2 that knows when streaming starts and stops.
>>>>
>>>> That's right, but pipeline start (which includes validation and resource
>>>> reservation) needs to be performed synchronously with VIDIOC_STREAMON.
>>>> The streaming state managed by vb2 is not relevant,
>>>> media_pipeline_start() must not be delayed the same way
>>>> .start_streaming() is.
>>>
>>> It will be the first thing that vb2_streamon calls. This has nothing to do
>>> with start_streaming: that's called when sufficient number of buffers are
>>> queued up to be able to start the DMA. This proposed prepare_streaming op
>>> will be called when VIDIOC_STREAMON is called.
>>
>> Then it doesn't need vb2's knowledge of the stream state :-)
>>
>>>>> The driver just
>>>>> needs to be informed (e.g. prepare_streaming and unprepare_streaming ops).
>>>>>
>>>>> vb2 deals with buffer management and it keeps track of the streaming state
>>>>> and makes the streaming state transitions. That *is* an integral part of
>>>>> vb2. What is missing at the moment are callbacks done at streamon time and
>>>>> when the streaming stops (streamoff, or close() when is_streaming is true).
>>>>>
>>>>> If you want to implement stream validation in a driver, then there are a
>>>>> lot of things you need to do:
>>>>>
>>>>> - override streamon, make sure you call vb2_queue_is_busy(), validate the
>>>>>   pipeline, then call vb2_streamon, if that fails, remember to stop the
>>>>>   pipeline.
>>>>>
>>>>> - override streamoff, make sure you call vb2_queue_is_busy(), stop the
>>>>>   pipeline and call vb2_streamoff.
>>>>>
>>>>> - in the release() function when the fh is closed, you have to check
>>>>>   vb2_is_streaming(), check that you are the owner of the queue, and if true,
>>>>>   stop the pipeline.
>>>>
>>>> I'm not opposed to helper functions to implement that, they can bundle
>>>> vb2 calls and pipeline management.
>>>>
>>>>> By moving this to vb2 ops all you need to implement are the prepare and
>>>>> unprepare ops.
>>>>>
>>>>> Esp. the release() implementation is tricky. I'm pretty sure that
>>>>> drivers/media/platform/samsung/exynos4-is/fimc-lite.c is wrong, since it
>>>>> should only call media_pipeline_stop() for the owner of the queue. Instead
>>>>> it calls it for the last user of the queue.
>>>>>
>>>>> I see that fimc_lite_streamoff() is wrong too: you can safely call
>>>>> VIDIOC_STREAMOFF twice: the second streamoff just returns 0 without
>>>>> doing anything. Instead media_pipeline_stop is called without testing if
>>>>> the queue is streaming.
>>>>>
>>>>> And yes, this is in part because V4L2 has quite some history and certainly
>>>>> API choice were made in the past that we wouldn't make today. But vb2
>>>>> shields you from that, and behaves much more like a proper state machine.
>>>>>
>>>>> I know you prefer to give a lot more control to driver developers, but
>>>>> in my experience very few developers can do things like this right. And
>>>>> it is really hard as a reviewer to check if all the corner cases are handled
>>>>> correctly in a driver. If vb2 is used, then I know things are called at the
>>>>> right time, and that makes my life as reviewer so much easier.
>>>>
>>>> It's not just about giving more control to drivers, it's about
>>>> organizing the software layers in a way that keeps them maintainable,
>>>> with layered abstractions and not midlayers.
>>>>
>>>> We are extensively reworking the media pipeline management as part of
>>>> the stream series, and there will be more work on top of that that will
>>>> make even more fundamental changes. I would like to at least postpone
>>>> any work on vb2 until then, to be able to evaluate the impact.
>>>
>>> I'll make an RFC patch for vb2 so you have a better idea of what it does.
>>
>> As long as we don't merge it before I get the chance to send the media
>> pipeline management rework, I'm all for RFCs :-)
>>
> 
> To unblock Eugen is it fine if he moves media_pipeline_start() at
> streamon() time for now ? It will require overriding
> v4l2_ioctl.vidioc_streamon which might be a bit of additional work
> (but probably easier to replace once a proper solution lands)
> 
> Otherwise, should the series go in as it is now ?

I had a comment about patch 6, so I want a new series anyway. All the
patches with just fixes (everything but 4 and 8) can go in once I have
them.

I think - all things considered - it is currently best to start and stop the
pipeline in start/stop_streaming: that at least avoids all the complications
with streamon/off/close() that is really hard to get right without (IMHO)
my proposed vb2 changes.

With that I will accept the series.

Regards,

	Hans

> 
> Thanks
>   j
> 
>>>>> There may still be a few drivers that really need to do this manually, and
>>>>> that's OK, but a driver like the atmel-isc doesn't need that at all.
>>
>> --
>> Regards,
>>
>> Laurent Pinchart