Re: [PATCH] media: mediatek: vcodec: Fix v4l2 compliance decoder cmd test fail

["yunfei.dong@mediatek.com" <yunfei.dong@mediatek.com>]

Hi Hans,

Thanks for your suggestion, I will resend patch v4 according to your
suggestion.

Best Regards,
Yunfei Dong
On Thu, 2022-04-21 at 12:47 +0200, Hans Verkuil wrote:
> On 06/04/2022 03:20, Yunfei Dong wrote:
> > Will return -EINVAL using standard framework api when test
> > stateless
> > decoder with cmd VIDIOC_(TRY)DECODER_CMD.
> > 
> > Using another return value to adjust v4l2 compliance test for user
> > driver(GStreamer/Chrome) won't use decoder cmd.
> > 
> > Fixes: 8cdc3794b2e3 ("media: mtk-vcodec: vdec: support stateless
> > API")
> > Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> > Reviewed-by: AngeloGioacchino Del Regno <
> > angelogioacchino.delregno@collabora.com>
> > ---
> > changes compared with v2:
> > - add reviewed-by tag
> > changes compared with v1:
> > - add Fixes: tag
> > ---
> >  drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git
> > a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
> > b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
> > index 3859e4c651c6..69b0e797d342 100644
> > --- a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
> > +++ b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_dec.c
> > @@ -51,8 +51,7 @@ static int vidioc_try_decoder_cmd(struct file
> > *file, void *priv,
> >  
> >  	/* Use M2M stateless helper if relevant */
> >  	if (ctx->dev->vdec_pdata->uses_stateless_api)
> > -		return v4l2_m2m_ioctl_stateless_try_decoder_cmd(file,
> > priv,
> > -								cmd);
> > +		return -ENOTTY;
> >  	else
> >  		return v4l2_m2m_ioctl_try_decoder_cmd(file, priv, cmd);
> >  }
> 
> So in other words, if the stateless api is used, then
> (TRY_)DECODER_CMD
> is not implemented. And that's because this driver doesn't set the
> V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF capability as that's not
> needed.
> And so there is no need for (TRY_)DECODER_CMD to be implemented.
> 
> If that's the case, then it is much better to just disable these two
> ioctls with v4l2_disable_ioctl() if the stateless API is used.
> 
> And just drop the uses_stateless_api checks in both
> vidioc_try_decoder_cmd
> and vidioc_decoder_cmd. This patch only changed
> vidioc_try_decoder_cmd,
> but of course vidioc_decoder_cmd needs to be modified as well.
> 
> Regards,
> 
> 	Hans