On 06/20/2016 11:01 AM, Ricardo Ribalda Delgado wrote:
> 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 changes the order when fill_user_buffer() is called,
> to follow the documentation.
>
> Reported-by: Dimitrios Katsaros <patcherw...@gmail.com>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.riba...@gmail.com>
Sorry, this won't work. Calling __vb2_dqbuf will overwrite the state
VB2_BUF_STATE_ERROR and so the V4L2_BUF_FLAG_ERROR flag will never be
set. The same is true for the last 'if' in the __fill_v4l2_buffer()
function.
I think it might be better to keep this code and instead change the
vb2_internal_dqbuf function to just clear the DONE flag after calling
vb2_core_dqbuf.
It would be nice to have a v4l2_compliance check for this as well.
Regards,
Hans
> ---
> drivers/media/v4l2-core/videobuf2-core.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/videobuf2-core.c
> b/drivers/media/v4l2-core/videobuf2-core.c
> index 633fc1ab1d7a..63981f28075e 100644
> --- a/drivers/media/v4l2-core/videobuf2-core.c
> +++ b/drivers/media/v4l2-core/videobuf2-core.c
> @@ -1771,10 +1771,6 @@ int vb2_core_dqbuf(struct vb2_queue *q, unsigned int
> *pindex, void *pb,
> if (pindex)
> *pindex = vb->index;
>
> - /* Fill buffer information for the userspace */
> - if (pb)
> - call_void_bufop(q, fill_user_buffer, vb, pb);
> -
> /* Remove from videobuf queue */
> list_del(&vb->queued_entry);
> q->queued_count--;
> @@ -1784,6 +1780,10 @@ int vb2_core_dqbuf(struct vb2_queue *q, unsigned int
> *pindex, void *pb,
> /* go back to dequeued state */
> __vb2_dqbuf(vb);
>
> + /* Fill buffer information for the userspace */
> + if (pb)
> + call_void_bufop(q, fill_user_buffer, vb, pb);
> +
> dprintk(1, "dqbuf of buffer %d, with state %d\n",
> vb->index, vb->state);
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
