Re: [PATCH 1/3] media: venus: Add support for static video encoder/decoder declarations

[Bryan O'Donoghue]

On 28/11/2024 20:02, Konrad Dybcio wrote:
> On 27.11.2024 2:34 AM, Bryan O'Donoghue wrote:
> > Add resource structure data and probe() logic to support static
> > declarations of encoder and decoder.
> >
> > Right now we rely on video encoder/decoder selection happening in the dtb
> > but, this goes against the remit of device tree which is supposed to
> > describe hardware, not select functional logic in Linux drivers.
> >
> > Provide two strings in the venus resource structure enc_nodename and
> > dec_nodename.
> >
> > When set the venus driver will create an OF entry in-memory consistent
> > with:
> >
> > dec_nodename {
> >      compat = "video-decoder";
> > };
> >
> > and/or
> >
> > enc_nodename {
> >      compat = "video-encoder";
> > };
> >
> > This will allow us to reuse the existing driver scheme of relying on compat
> > names maintaining compatibility with old dtb files.
> >
> > dec_nodename can be "video-decoder" or "video0"
> > enc_nodename can be "video-encoder" or "video1"
> >
> > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
> > ---
>
> Bryan,
>
> I'm still not sure if keeping the logic behind this makes sense at all.
>
> Could we not just call platform_device_register_data() with a static
> configuration of 1 core being enc and the other dec?

That's another way to do this. One reason I wrote this series to 
continue to rely on the existing compat= method though is it stuck in my 
mind that we have some dependency ordering logic in at the moment.

For example:

commit 08b1cf474b7f72750adebe0f0a35f8e9a3eb75f6
Author: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
Date:   Fri Feb 5 19:11:49 2021 +0100

And the other reason is the prototype platform_device_register_* looks 
like more surgery and ultimately more validation / potential for bugs.

Since this driver is supposed to be moving to maintenance mode, I didn't 
want to do a more major rewrite of the probe() and remove() paths.

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