Re: [PATCH v9 19/28] rcar-vin: use different v4l2 operations in media controller mode

Niklas Söderlund
2018-01-19T00:46:07Z

Hi Laurent,

Thanks for your comments.

Apart from the issue with the input API Hans pointed which indicates I
need to keep that around until it's fixed in the framework I agree with
all your comments but one.

<snip>

On 2017-12-08 12:14:05 +0200, Laurent Pinchart wrote:
> > @@ -628,7 +628,8 @@ static int rvin_setup(struct rvin_dev *vin)
> > /* Default to TB */
> > vnmc = VNMC_IM_FULL;
> > /* Use BT if video standard can be read and is 60 Hz format */
> > - if (!v4l2_subdev_call(vin_to_source(vin), video, g_std, &std)) {
> > + if (!vin->info->use_mc &&
> > + !v4l2_subdev_call(vin_to_source(vin), video, g_std, &std)) {
> > if (std & V4L2_STD_525_60)
> > vnmc = VNMC_IM_FULL | VNMC_FOC;
> > }
>
> I think the subdev should be queried in rcar-v4l2.c and the information cached
> in the rvin_dev structure instead of queried here. Interactions with the
> subdev should be minimized in rvin-dma.c. You can fix this in a separate patch
> if you prefer.
>

This can't be a cached value it needs to be read at stream on time. The
input source could have changed format, e.g. the user may have
disconnected a NTSC source and plugged in a PAL.

This is a shame as I otherwise agree with you that interactions with the
subdevice should be kept at a minimum.

<snip>

--
Regards,
Niklas Söderlund