[libcamera-devel] Undefined MC-centric behaviour

[Laurent Pinchart]

Hi Marco,

On Wed, May 05, 2021 at 05:09:17PM +0200, Marco Felsch wrote:
> Hi all,
> 
> first of all hopefully I got most of you within To: or Cc:.
> 
> During making the iMX6 IPU driver MC-cenric compatible without breaking
> backward compatibility we noticed that the API/API-Doc don't mention the
> behviour for:
>  - vidioc_enum_framesizes()
>  - vidioc_enum_frameintervals()
> 
> I our opinion:
>  - vidioc_enum_framesizes(): should only limit to the DMA restrictions

Sounds good I think. Should we then document that the ioctl should
return a single continuous or stepwise range ? I can't really imagine
the DMA engine limits to require discrete enumeration.

>  - vidioc_enum_frameintervals(): should return nothing since it is up to
>    user space to select the correct one from the last downstream
>    v4l2-subdev element (_not_ the sensor).

Why not the sensor ? The frame interval is set by the source, isn't it ?

> Now the discussion can start :)

Thanks for quickstarting this :-)

-- 
Regards,

Laurent Pinchart