| Message ID | 20210907124751.6404-1-linux@weissschuh.net |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] backlight: propagate errors from get_brightness() | expand |
On 2021-09-07T14:10+0100, Daniel Thompson wrote: > On Tue, Sep 07, 2021 at 02:47:51PM +0200, Thomas Weißschuh wrote: > > backlight.h documents "struct backlight_ops->get_brightness()" to return > > a negative errno on failure. > > So far these errors have not been handled in the backlight core. > > This leads to negative values being exposed through sysfs although only > > positive values are documented to be reported. > > > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > > Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Thanks! Thomas
On 2021-09-07T14:47+0200, Thomas Weißschuh wrote: > backlight.h documents "struct backlight_ops->get_brightness()" to return > a negative errno on failure. > So far these errors have not been handled in the backlight core. > This leads to negative values being exposed through sysfs although only > positive values are documented to be reported. > [..] Friendly ping.
On Tue, 21 Sep 2021, Thomas Weißschuh wrote: > On 2021-09-07T14:47+0200, Thomas Weißschuh wrote: > > backlight.h documents "struct backlight_ops->get_brightness()" to return > > a negative errno on failure. > > So far these errors have not been handled in the backlight core. > > This leads to negative values being exposed through sysfs although only > > positive values are documented to be reported. > > > [..] > > Friendly ping. Don't do that. If you think the submission has been forgotten about (it hasn't), then please submit a [RESEND]. As it happens, this is on my TOREVEW list. I just need to get around to it post-vacation. -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog
On Tue, 07 Sep 2021, Thomas Weißschuh wrote: > backlight.h documents "struct backlight_ops->get_brightness()" to return > a negative errno on failure. > So far these errors have not been handled in the backlight core. > This leads to negative values being exposed through sysfs although only > positive values are documented to be reported. > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > --- > > v1: https://lore.kernel.org/dri-devel/20210906215525.15418-1-linux@weissschuh.net/ > > v1 -> v2: > * use dev_err() instead of dev_warn() (Daniel Thompson) > * Finish logging format string with newline (Daniel Thompson) > * Log errno via dedicated error pointer format (Daniel Thompson) > > drivers/video/backlight/backlight.c | 22 +++++++++++++++++----- > 1 file changed, 17 insertions(+), 5 deletions(-) Applied, thanks. -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog
On 2021-09-23T10:48+0100, Lee Jones wrote: > On Tue, 07 Sep 2021, Thomas Weißschuh wrote: > > > backlight.h documents "struct backlight_ops->get_brightness()" to return > > a negative errno on failure. > > So far these errors have not been handled in the backlight core. > > This leads to negative values being exposed through sysfs although only > > positive values are documented to be reported. > > > > Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> > > --- > > > > v1: https://lore.kernel.org/dri-devel/20210906215525.15418-1-linux@weissschuh.net/ > > > > v1 -> v2: > > * use dev_err() instead of dev_warn() (Daniel Thompson) > > * Finish logging format string with newline (Daniel Thompson) > > * Log errno via dedicated error pointer format (Daniel Thompson) > > > > drivers/video/backlight/backlight.c | 22 +++++++++++++++++----- > > 1 file changed, 17 insertions(+), 5 deletions(-) > > Applied, thanks. Hi Lee, thanks! Also I'm sorry about my nagging before. I was not aware you were on vacation and saw you respond to other mails. Thomas
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 537fe1b376ad..4658cfb75aa2 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -292,10 +292,13 @@ static ssize_t actual_brightness_show(struct device *dev, struct backlight_device *bd = to_backlight_device(dev); mutex_lock(&bd->ops_lock); - if (bd->ops && bd->ops->get_brightness) - rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd)); - else + if (bd->ops && bd->ops->get_brightness) { + rc = bd->ops->get_brightness(bd); + if (rc >= 0) + rc = sprintf(buf, "%d\n", rc); + } else { rc = sprintf(buf, "%d\n", bd->props.brightness); + } mutex_unlock(&bd->ops_lock); return rc; @@ -381,9 +384,18 @@ ATTRIBUTE_GROUPS(bl_device); void backlight_force_update(struct backlight_device *bd, enum backlight_update_reason reason) { + int brightness; + mutex_lock(&bd->ops_lock); - if (bd->ops && bd->ops->get_brightness) - bd->props.brightness = bd->ops->get_brightness(bd); + if (bd->ops && bd->ops->get_brightness) { + brightness = bd->ops->get_brightness(bd); + if (brightness >= 0) + bd->props.brightness = brightness; + else + dev_err(&bd->dev, + "Could not update brightness from device: %pe\n", + ERR_PTR(brightness)); + } mutex_unlock(&bd->ops_lock); backlight_generate_event(bd, reason); }
backlight.h documents "struct backlight_ops->get_brightness()" to return a negative errno on failure. So far these errors have not been handled in the backlight core. This leads to negative values being exposed through sysfs although only positive values are documented to be reported. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> --- v1: https://lore.kernel.org/dri-devel/20210906215525.15418-1-linux@weissschuh.net/ v1 -> v2: * use dev_err() instead of dev_warn() (Daniel Thompson) * Finish logging format string with newline (Daniel Thompson) * Log errno via dedicated error pointer format (Daniel Thompson) drivers/video/backlight/backlight.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) base-commit: 79fad92f2e596f5a8dd085788a24f540263ef887