This is a note to let you know that I've just added the patch titled
[media] vb2: V4L2_BUF_FLAG_DONE is set after DQBUF
to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: vb2-v4l2_buf_flag_done-is-set-after-dqbuf.patch and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 3171cc2b4eb9831ab4df1d80d0410a945b8bc84e Mon Sep 17 00:00:00 2001
From: Ricardo Ribalda ricardo.ribalda@gmail.com Date: Mon, 20 Jun 2016 09:47:22 -0300 Subject: [media] vb2: V4L2_BUF_FLAG_DONE is set after DQBUF
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: Sasha Levin alexander.levin@microsoft.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-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; }
Patches currently in stable-queue which might be from ricardo.ribalda@gmail.com are
queue-3.18/vb2-v4l2_buf_flag_done-is-set-after-dqbuf.patch