From 04990215dec43c424daff00d1f622167b8aafd1f Mon Sep 17 00:00:00 2001
From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Date: Wed, 28 Nov 2018 03:37:43 -0500
Subject: [PATCH] media: vb2: don't call __vb2_queue_cancel if
 vb2_start_streaming failed
Git-commit: 04990215dec43c424daff00d1f622167b8aafd1f
Patch-mainline: v4.20
References: bsc#1119086

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: Oliver Neukum <oneukum@suse.com>
---
 drivers/media/common/videobuf2/videobuf2-core.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 975ff5669f72..e006698807fa 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1940,10 +1940,8 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type)
 		if (ret)
 			return ret;
 		ret = vb2_start_streaming(q);
-		if (ret) {
-			__vb2_queue_cancel(q);
+		if (ret)
 			return ret;
-		}
 	}
 
 	q->streaming = 1;
-- 
2.16.4