On 11/19/19 12:34 PM, Hans Verkuil wrote:
> Stateful encoders need to know if V4L2_BUF_FLAG_ERROR was because
> the capture buffer was too small or because there was another
> error. Set this flag (always in combination with FLAG_ERROR) to
> indicate that the buffer was too small.
>
> A corresponding VB2_BUF_STATE_ERROR_TOO_SMALL vb2 state was added.
>
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
> ---
> Documentation/media/uapi/v4l/buffer.rst | 9 +++++++++
> drivers/media/common/videobuf2/videobuf2-core.c | 12 +++++++++---
> drivers/media/common/videobuf2/videobuf2-v4l2.c | 4 ++++
> include/media/videobuf2-core.h | 4 ++++
> include/uapi/linux/videodev2.h | 2 ++
> 5 files changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst
> index 9149b57728e5..64a97677ec20 100644
> --- a/Documentation/media/uapi/v4l/buffer.rst
> +++ b/Documentation/media/uapi/v4l/buffer.rst
> @@ -540,6 +540,15 @@ Buffer Flags
> streaming may continue as normal and the buffer may be reused
> normally. Drivers set this flag when the ``VIDIOC_DQBUF`` ioctl is
> called.
> + * .. _`V4L2-BUF-FLAG-TOO-SMALL`:
> +
> + - ``V4L2_BUF_FLAG_TOO_SMALL``
> + - 0x00080000
> + - When this flag is set, the buffer has been dequeued successfully,
> + but no data was written since the buffer was too small. If this
> + flag is set, then ``V4L2_BUF_FLAG_ERROR`` was also set. This can
> + only happen for capture buffers. Drivers set this flag when
> + the ``VIDIOC_DQBUF`` ioctl is called.
> * .. _`V4L2-BUF-FLAG-IN-REQUEST`:
>
> - ``V4L2_BUF_FLAG_IN_REQUEST``
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index 4489744fbbd9..187a4589a7bb 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -929,6 +929,7 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
>
> if (WARN_ON(state != VB2_BUF_STATE_DONE &&
> state != VB2_BUF_STATE_ERROR &&
> + state != VB2_BUF_STATE_ERROR_TOO_SMALL &&
> state != VB2_BUF_STATE_QUEUED))
> state = VB2_BUF_STATE_ERROR;
>
> @@ -1816,6 +1817,9 @@ int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
> case VB2_BUF_STATE_ERROR:
> dprintk(3, "returning done buffer with errors\n");
> break;
> + case VB2_BUF_STATE_ERROR_TOO_SMALL:
> + dprintk(3, "returning done buffer that's too small\n");
> + break;
> default:
> dprintk(1, "invalid buffer state\n");
> return -EINVAL;
> @@ -2383,8 +2387,9 @@ __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
> done_entry);
> spin_unlock_irqrestore(&q->done_lock, flags);
>
> - if (vb && (vb->state == VB2_BUF_STATE_DONE
> - || vb->state == VB2_BUF_STATE_ERROR)) {
> + if (vb && (vb->state == VB2_BUF_STATE_DONE ||
> + vb->state == VB2_BUF_STATE_ERROR ||
> + vb->state == VB2_BUF_STATE_ERROR_TOO_SMALL)) {
> return (q->is_output) ?
> EPOLLOUT | EPOLLWRNORM :
> EPOLLIN | EPOLLRDNORM;
> @@ -2812,7 +2817,8 @@ static int vb2_thread(void *data)
> break;
> try_to_freeze();
>
> - if (vb->state != VB2_BUF_STATE_ERROR)
> + if (vb->state != VB2_BUF_STATE_ERROR &&
> + vb->state != VB2_BUF_STATE_ERROR_TOO_SMALL)
> if (threadio->fnc(vb, threadio->priv))
> break;
> call_void_qop(q, wait_finish, q);
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index e652f4318284..6ac19734e4a2 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -44,6 +44,7 @@ module_param(debug, int, 0644);
> /* Flags that are set by us */
> #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
> V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
> + V4L2_BUF_FLAG_ERROR_TOO_SMALL | \
Oops, should have been V4L2_BUF_FLAG_TOO_SMALL. Sorry about that.
Regards,
Hans
