Re: [PATCH v2 2/2] v4l: Add support for STD ioctls on subdev nodes

[Mauro Carvalho Chehab <mchehab+samsung@kernel.org>]

Em Thu, 17 May 2018 16:30:16 +0200
Niklas Söderlund         <niklas.soderlund+renesas@ragnatech.se> escreveu:

> There is no way to control the standard of subdevices which are part of
> a media device. The ioctls which exists all target video devices
> explicitly and the idea is that the video device should talk to the
> subdevice. For subdevices part of a media graph this is not possible and
> the standard must be controlled on the subdev device directly.

Why isn't it possible? A media pipeline should have at least a video
devnode where the standard ioctls will be issued.

So, I don't see why you would need to explicitly set the standard inside
a sub-device.

The way I see, inside a given pipeline, all subdevs should be using the
same video standard (maybe except for a m2m device with would have some
coded that would be doing format conversion).

Am I missing something?

Thanks,
Mauro