@@ -43,6 +43,7 @@ struct mxc_isi_m2m_ctx_queue_data {
struct v4l2_pix_format_mplane format;
const struct mxc_isi_format_info *info;
u32 sequence;
+ bool streaming;
};
struct mxc_isi_m2m_ctx {
@@ -486,6 +487,7 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh,
enum v4l2_buf_type type)
{
struct mxc_isi_m2m_ctx *ctx = to_isi_m2m_ctx(fh);
+ struct mxc_isi_m2m_ctx_queue_data *q = mxc_isi_m2m_ctx_qdata(ctx, type);
const struct v4l2_pix_format_mplane *out_pix = &ctx->queues.out.format;
const struct v4l2_pix_format_mplane *cap_pix = &ctx->queues.cap.format;
const struct mxc_isi_format_info *cap_info = ctx->queues.cap.info;
@@ -495,6 +497,9 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh,
int ret;
+ if (q->streaming)
+ return 0;
+
mutex_lock(&m2m->lock);
if (m2m->usage_count == INT_MAX) {
@@ -547,6 +552,8 @@ static int mxc_isi_m2m_streamon(struct file *file, void *fh,
goto unchain;
}
+ q->streaming = true;
+
return 0;
unchain:
@@ -569,10 +576,14 @@ static int mxc_isi_m2m_streamoff(struct file *file, void *fh,
enum v4l2_buf_type type)
{
struct mxc_isi_m2m_ctx *ctx = to_isi_m2m_ctx(fh);
+ struct mxc_isi_m2m_ctx_queue_data *q = mxc_isi_m2m_ctx_qdata(ctx, type);
struct mxc_isi_m2m *m2m = ctx->m2m;
v4l2_m2m_ioctl_streamoff(file, fh, type);
+ if (!q->streaming)
+ return 0;
+
mutex_lock(&m2m->lock);
/*
@@ -598,6 +609,8 @@ static int mxc_isi_m2m_streamoff(struct file *file, void *fh,
mutex_unlock(&m2m->lock);
+ q->streaming = false;
+
return 0;
}
Currently, if streamon/streamoff calls are imbalanced we can either end up with a negative ISI m2m usage_count (if streamoff() is called more times than streamon()) in which case we'll not be able to restart the ISI pipe next time, or the usage_count never gets to 0 and the pipe is never switched off. To avoid that, add a 'streaming' flag to mxc_isi_m2m_ctx_queue_data and use it in the streamon/streamoff to avoid incrementing/decrementing the usage_count uselessly, if called multiple times from the same context. Fixes: cf21f328fcafac ("media: nxp: Add i.MX8 ISI driver") Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com> --- v3: * Changed the implementation as suggested by Laurent and add a Suggested-by tag to reflect that; v2: * Changed the way 'usage_count' is incremented/decremented by taking into account the context the streamon/streamoff functions are called from; * Changed the commit message and subject to reflect the changes; drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)