Re: [PATCH v1 4/5] media: venus: video decoder drop frames handling

[Tomasz Figa]

On Sat, Sep 29, 2018 at 9:01 PM Srinu Gorle <sgorle@xxxxxxxxxxxxxx> wrote:
>
> - when drop frame flag received from venus h/w, reset buffer
>   parameters and update v4l2 buffer flags as error buffer.
>
> Signed-off-by: Srinu Gorle <sgorle@xxxxxxxxxxxxxx>
> ---
>  drivers/media/platform/qcom/venus/vdec.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/media/platform/qcom/venus/vdec.c b/drivers/media/platform/qcom/venus/vdec.c
> index 0035cf2..311f209 100644
> --- a/drivers/media/platform/qcom/venus/vdec.c
> +++ b/drivers/media/platform/qcom/venus/vdec.c
> @@ -991,6 +991,12 @@ static void vdec_buf_done(struct venus_inst *inst, unsigned int buf_type,
>         if (hfi_flags & HFI_BUFFERFLAG_DATACORRUPT)
>                 state = VB2_BUF_STATE_ERROR;
>
> +       if (hfi_flags & HFI_BUFFERFLAG_DROP_FRAME) {
> +               vb->planes[0].bytesused = 0;
> +               vb->timestamp = 0;
> +               state = VB2_BUF_STATE_ERROR;
> +       }

What does this HFI_BUFFERFLAG_DROP_FRAME flag mean? When would it
happen? I assume it applies only to CAPTURE buffers, since for OUTPUT
buffers you must not set the bytesuses/timestamp yourself, right? Is
the buffer guaranteed to have no decoded frame inside or the frame
could be there, but incomplete/corrupted?

Best regards,
Tomasz