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


From: Ricardo Ribalda <ricardo.riba...@gmail.com>

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,

This patch forces FLAG_DONE to 0 after calling DQBUF.

Reported-by: Dimitrios Katsaros <patcherw...@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.riba...@gmail.com>
Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mche...@s-opensource.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
Signed-off-by: Mauro Carvalho Chehab <mche...@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

 drivers/media/v4l2-core/videobuf2-core.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -2075,6 +2075,11 @@ static int vb2_internal_dqbuf(struct vb2
        dprintk(1, "dqbuf of buffer %d, with state %d\n",
                        vb->v4l2_buf.index, vb->state);
+       /*
+        * After calling the VIDIOC_DQBUF V4L2_BUF_FLAG_DONE must be
+        * cleared.
+        */
+       b->flags &= ~V4L2_BUF_FLAG_DONE;
        return 0;

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