[PATCH 4.4 072/108] vb2: V4L2_BUF_FLAG_DONE is set after DQBUF

[Greg Kroah-Hartman]

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

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

From: Ricardo Ribalda <ricardo.ribalda@xxxxxxxxx>

commit 3171cc2b4eb9831ab4df1d80d0410a945b8bc84e upstream.

According to the doc, V4L2_BUF_FLAG_DONE is cleared after DQBUF:

V4L2_BUF_FLAG_DONE 0x00000004  ... After calling the VIDIOC_QBUF or
VIDIOC_DQBUF it is always cleared ...

Unfortunately, it seems that videobuf2 keeps it set after DQBUF. This
can be tested with vivid and dev_debug:

[257604.338082] video1: VIDIOC_DQBUF: 71:33:25.00260479 index=3,
type=vid-cap, flags=0x00002004, field=none, sequence=163,
memory=userptr, bytesused=460800, offset/userptr=0x344b000,
length=460800

This patch forces FLAG_DONE to 0 after calling DQBUF.

Reported-by: Dimitrios Katsaros <patcherwork@xxxxxxxxx>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/media/v4l2-core/videobuf2-v4l2.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/media/v4l2-core/videobuf2-v4l2.c
+++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
@@ -593,6 +593,12 @@ static int vb2_internal_dqbuf(struct vb2
 			b->flags & V4L2_BUF_FLAG_LAST)
 		q->last_buffer_dequeued = true;
 
+	/*
+	 *  After calling the VIDIOC_DQBUF V4L2_BUF_FLAG_DONE must be
+	 *  cleared.
+	 */
+	b->flags &= ~V4L2_BUF_FLAG_DONE;
+
 	return ret;
 }