Re: [PATCH v3 1/3] media: rkvdec: Fix .buf_prepare

[Tomasz Figa <tfiga@chromium.org>]

Hi Ezequiel,

On Tue, May 5, 2020 at 3:41 PM Ezequiel Garcia <ezequiel@collabora.com> 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.

Thanks for the patch. Just one question below.

Where does the requirement to set OUTPUT buffer bytesused to sizeimage
if the original bytesused is 0 come from?

Best regards,
Tomasz

>
> Fix it.
>
> Fixes: cd33c830448ba ("media: rkvdec: Add the rkvdec driver")
> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> ---
>  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);
>         return 0;
>  }
>
> --
> 2.26.0.rc2
>