4.4-stable review patch. If anyone has any objections, please let me know.
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From: Ricardo Ribalda ricardo.ribalda@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, length=460800
This patch forces FLAG_DONE to 0 after calling DQBUF.
Reported-by: Dimitrios Katsaros patcherwork@gmail.com Signed-off-by: Ricardo Ribalda Delgado ricardo.ribalda@gmail.com Signed-off-by: Hans Verkuil hans.verkuil@cisco.com Signed-off-by: Mauro Carvalho Chehab mchehab@s-opensource.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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; }