[PATCH 4.9 001/118] media: videobuf2-v4l2: drop WARN_ON in vb2_warn_zero_bytesused()

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>

commit 5e99456c20f712dcc13d9f6ca4278937d5367355 upstream.

Userspace shouldn't set bytesused to 0 for output buffers.
vb2_warn_zero_bytesused() warns about this (only once!), but it also
calls WARN_ON(1), which is confusing since it is not immediately clear
that it warns about a 0 value for bytesused.

Just drop the WARN_ON as it serves no purpose.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Acked-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Cc: Matthias Maennich <maennich@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/media/v4l2-core/videobuf2-v4l2.c |    1 -
 1 file changed, 1 deletion(-)

--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -146,7 +146,6 @@ static void vb2_warn_zero_bytesused(stru
 		return;
 
 	check_once = true;
-	WARN_ON(1);
 
 	pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
 	if (vb->vb2_queue->allow_zero_bytesused)