Re: [yavta PATCH 5/9] Allow passing file descriptors to yavta

[Sakari Ailus <sakari.ailus@iki.fi>]

Hi Laurent,

Laurent Pinchart wrote:
> Just thinking out loud, we need to
>
> - initialize the device structure,
> - open the device or use an externally provided fd,
> - optionally query the device capabilities,
> - optionally override the queue type.
>
> Initializing the device structure must be performed unconditionally, I would
> create a video_init() function for that.

This is now performed in the beginning of main(). video_open() no longer 
initialises anything.

> Opening the device or using an externally provided fd are exclusive
> operations, I would create two functions (that wouldn't do much).

Currently this is a few lines in main().

> Querying the device capabilities is also optional, I would create one function
> for that.

Patch 4/9.

> Finally, overriding the queue type is of course optional and should be
> implemented in its own function. We should probably return an error if the
> user tries to set a queue type not reported by QUERYCAP (assuming QUERYCAP has
> been called).

The same check already done in the driver, and an error is returned if 
it's wrong. I'm leaning towards thinking this isn't necessary in yavta.

> Ideally I'd also like to make the --no-query argument non-mandatory when
> operating on subdev nodes. It has been introduced because QUERYCAP isn't
> supported by subdev nodes, and it would be nice if we could detect somehow
> that the device node corresponds to a subdev and automatically skip QUERYCAP
> in that case.

It's already non-mandatory. We don't try to rocognise sub-device nodes, 
but failing querycap is a non-error already without this patchset.

-- 
Regards,

Sakari Ailus
sakari.ailus@iki.fi