Re: [PATCH v3 3/3] platform/surface: Add OF support

Andy Shevchenko
2024-08-28T19:07:08Z

On Wed, Aug 28, 2024 at 8:40 PM Maximilian Luz <luzmaximilian@gmail.com> wrote:
> On 8/28/24 6:56 PM, Andy Shevchenko wrote:
> > On Wed, Aug 28, 2024 at 12:10 PM Maximilian Luz <luzmaximilian@gmail.com> wrote:

...

> > Yes, and software nodes for DT are quite strange things! Why can't you
> > simply fix the DT to begin with?
>
> For the ARM/DT variants we could do that. But we still have to deal with
> the x86/ACPI ones here.

So, then fix it there! Currently it's an abuse of software nodes
inside the Linux kernel.

> So for me it makes more sense to have it unified
> and just deal with everything in this module.

I understand the desire, but DT is DT and ACPI is ACPI, they are
different despite having some common APIs in the Linux kernel.
Moreover, DT has a validation tools and everything, making that being
a software nodes has at least these disadvantages:
- no official schema that must be supported and users are known of
- no validation done
- bloating of the Linux kernel binary and hence memory footprint

> Also, if we consider that at some point we might get ACPI PEP support (I
> know, far fetched right now): With that, ACPI on ARM might be feasible
> and then we'd have to manage the same thing in two places...

This (PEP) is something I have no knowledge about. But I think it's
still orthogonal to the software nodes usage.

> And lastly, the EC subdevices are quite contained and I don't see them
> interacting with any other components in the DT, so it's more of a
> stylistic choice where to put them.

They are still part of hardware and DT describes hardware.

--
With Best Regards,
Andy Shevchenko