[PATCH 4.19 30/44] media: vb2: dont call __vb2_queue_cancel if vb2_start_streaming failed

Greg Kroah-Hartman
2018-12-18T16:41:49Z

From: Hans Verkuil <hverkuil-cisco@xs4all.nl>

commit 04990215dec43c424daff00d1f622167b8aafd1f upstream.

vb2_start_streaming() already rolls back the buffers, so there is no
need to call __vb2_queue_cancel(). Especially since __vb2_queue_cancel()
does too much, such as zeroing the q->queued_count value, causing vb2
to think that no buffers have been queued.

It appears that this call to __vb2_queue_cancel() is a left-over from
before commit b3379c6201bb3.

Fixes: b3379c6201bb3 ('vb2: only call start_streaming if sufficient buffers are queued')

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: <stable@vger.kernel.org> # for v4.16 and up
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/common/videobuf2/videobuf2-core.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -1755,10 +1755,8 @@ int vb2_core_streamon(struct vb2_queue *
if (ret)
return ret;
ret = vb2_start_streaming(q);
- if (ret) {
- __vb2_queue_cancel(q);
+ if (ret)
return ret;
- }
}

q->streaming = 1;