From: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx> [ 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> --- drivers/media/platform/qcom/camss/camss-video.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/media/platform/qcom/camss/camss-video.c b/drivers/media/platform/qcom/camss/camss-video.c index 81fb3a5bc1d5..41deda232e4a 100644 --- a/drivers/media/platform/qcom/camss/camss-video.c +++ b/drivers/media/platform/qcom/camss/camss-video.c @@ -495,7 +495,7 @@ static int video_start_streaming(struct vb2_queue *q, unsigned int count) ret = video_device_pipeline_start(vdev, &video->pipe); if (ret < 0) - return ret; + goto flush_buffers; ret = video_check_format(video); if (ret < 0) @@ -524,6 +524,7 @@ static int video_start_streaming(struct vb2_queue *q, unsigned int count) error: video_device_pipeline_stop(vdev); +flush_buffers: video->ops->flush_buffers(video, VB2_BUF_STATE_QUEUED); return ret; -- 2.35.1