This is a note to let you know that I've just added the patch titled media: camss: Clean up received buffers on failed start of streaming to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: media-camss-clean-up-received-buffers-on-failed-star.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9d41042e37642dfa67c3659a33d8a52f0dbbafab Author: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx> Date: Mon Jul 4 10:44:37 2022 +0100 media: camss: Clean up received buffers on failed start of streaming [ Upstream commit c8f3582345e6a69da65ab588f7c4c2d1685b0e80 ] It is required to return the received buffers, if streaming can not be started. For instance media_pipeline_start() may fail with EPIPE, if a link validation between entities is not passed, and in such a case a user gets a kernel warning: WARNING: CPU: 1 PID: 520 at drivers/media/common/videobuf2/videobuf2-core.c:1592 vb2_start_streaming+0xec/0x160 <snip> Call trace: vb2_start_streaming+0xec/0x160 vb2_core_streamon+0x9c/0x1a0 vb2_ioctl_streamon+0x68/0xbc v4l_streamon+0x30/0x3c __video_do_ioctl+0x184/0x3e0 video_usercopy+0x37c/0x7b0 video_ioctl2+0x24/0x40 v4l2_ioctl+0x4c/0x70 The fix is to correct the error path in video_start_streaming() of camss. Fixes: 0ac2586c410f ("media: camss: Add files which handle the video device nodes") Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx> Reviewed-by: Robert Foss <robert.foss@xxxxxxxxxx> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/media/platform/qcom/camss/camss-video.c b/drivers/media/platform/qcom/camss/camss-video.c index 15965e63cb61..9333a7a33d4d 100644 --- a/drivers/media/platform/qcom/camss/camss-video.c +++ b/drivers/media/platform/qcom/camss/camss-video.c @@ -444,7 +444,7 @@ static int video_start_streaming(struct vb2_queue *q, unsigned int count) ret = media_pipeline_start(&vdev->entity, &video->pipe); if (ret < 0) - return ret; + goto flush_buffers; ret = video_check_format(video); if (ret < 0) @@ -473,6 +473,7 @@ static int video_start_streaming(struct vb2_queue *q, unsigned int count) error: media_pipeline_stop(&vdev->entity); +flush_buffers: video->ops->flush_buffers(video, VB2_BUF_STATE_QUEUED); return ret;