Re: [PATCH v3 0/4] Add post-init-providers binding to improve suspend/resume stability

[Saravana Kannan]

On Thu, Feb 22, 2024 at 5:34 AM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Wed, Feb 21, 2024 at 03:30:20PM -0800, Saravana Kannan wrote:
> > This patch series adds a "post-init-providers" device tree binding that
> > can be used to break dependency cycles in device tree and enforce a more
> > determinstic probe/suspend/resume order. This will also improve the
> > stability of global async probing and async suspend/resume and allow us
> > to enable them more easily. Yet another step away from playing initcall
> > chicken with probing and step towards fully async probing and
> > suspend/resume.
>
> Do you know what is the state of affairs in ACPI? Is there any (similar)
> issue even possible?

I'm not very familiar with ACPI, but I wouldn't be surprised if ACPI
devices have cyclic dependencies. But then ACPI on a PC doesn't
typically have as many devices/drivers and ACPI might be hiding the
dependencies from the kernel. So maybe the possibility of a cycle
visible to the kernel might be low.

I would really like to see fw_devlink extended to ACPI (it's written
in a way to make that possible), but don't have enough knowledge to do
it.

-Saravana