[PATCH 6.1 0302/1146] media: camss: Clean up received buffers on failed start of streaming

Greg Kroah-Hartman
2022-12-28T15:38:19Z

From: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>

[ 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@linaro.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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