[PATCH] media: uvcvideo: Return queued buffers on start_streaming() failure

[Michal Pecio <michal.pecio@gmail.com>]

Return buffers if streaming fails to start due to uvc_pm_get() error.

This bug may be responsible for a warning I got running

    while :; do yavta -c3 /dev/video0; done

on an xHCI controller which failed under this workload.
I had no luck reproducing this warning again to confirm.

xhci_hcd 0000:09:00.0: HC died; cleaning up
usb 13-2: USB disconnect, device number 2
WARNING: CPU: 2 PID: 29386 at drivers/media/common/videobuf2/videobuf2-core.c:1803 vb2_start_streaming+0xac/0x120

Fixes: 7dd56c47784a ("media: uvcvideo: Remove stream->is_streaming field")
Cc: stable@vger.kernel.org
Signed-off-by: Michal Pecio <michal.pecio@gmail.com>
---
 drivers/media/usb/uvc/uvc_queue.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 790184c9843d..f49c538618bc 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -177,7 +177,7 @@ static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
 
 	ret = uvc_pm_get(stream->dev);
 	if (ret)
-		return ret;
+		goto return_buffers;
 
 	queue->buf_used = 0;
 
@@ -187,6 +187,7 @@ static int uvc_start_streaming_video(struct vb2_queue *vq, unsigned int count)
 
 	uvc_pm_put(stream->dev);
 
+return_buffers:
 	uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
 
 	return ret;
-- 
2.48.1