On 18/05/2020 19:40, Ezequiel Garcia wrote:
> The driver should only set the payload on .buf_prepare
> if the buffer is CAPTURE type, or if an OUTPUT buffer
> has a zeroed payload.
>
> Fix it.
>
> Fixes: cd33c830448ba ("media: rkvdec: Add the rkvdec driver")
> Signed-off-by: Ezequiel Garcia <[email protected]>
> ---
> drivers/staging/media/rkvdec/rkvdec.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/media/rkvdec/rkvdec.c
> b/drivers/staging/media/rkvdec/rkvdec.c
> index 225eeca73356..4df2a248ab96 100644
> --- a/drivers/staging/media/rkvdec/rkvdec.c
> +++ b/drivers/staging/media/rkvdec/rkvdec.c
> @@ -456,7 +456,15 @@ static int rkvdec_buf_prepare(struct vb2_buffer *vb)
> if (vb2_plane_size(vb, i) < sizeimage)
> return -EINVAL;
> }
> - vb2_set_plane_payload(vb, 0, f->fmt.pix_mp.plane_fmt[0].sizeimage);
> +
> + /*
> + * Buffer's bytesused is written by the driver for CAPTURE buffers,
> + * or if the application passed zero bytesused on an OUTPUT buffer.
> + */
> + if (!V4L2_TYPE_IS_OUTPUT(vq->type) ||
> + (V4L2_TYPE_IS_OUTPUT(vq->type) && !vb2_get_plane_payload(vb, 0)))
> + vb2_set_plane_payload(vb, 0,
> + f->fmt.pix_mp.plane_fmt[0].sizeimage);
This should just be:
if (!V4L2_TYPE_IS_OUTPUT(vq->type))
vb2_set_plane_payload(vb, 0,
f->fmt.pix_mp.plane_fmt[0].sizeimage);
If the application passes 0 as bytesused, then 1) a warning will be generated
by the v4l2 core and 2) the v4l2 core will set bytesused to the length of the
buffer. See vb2_fill_vb2_v4l2_buffer() in videobuf2-v4l2.c.
Some old drivers explicitly allow bytesused to be 0 for an output queue to
signal end-of-stream, but that's only supported if the allow_zero_bytesused
flag is set in the vb2_queue, and that shall not be used for new drivers
since it is deprecated functionality.
Regards,
Hans
> return 0;
> }
>
>
