Re: [PATCH V4 1/8] drivers/acpi: Add support for Wifi band RF mitigations

Johannes Berg
2023-06-21T22:20:07Z

On Wed, 2023-06-21 at 21:25 +0200, Andrew Lunn wrote:
> > ACPI core does has notifiers that are used, but they don't work the same.
> > If you look at patch 4, you'll see amdgpu registers and unregisters using
> > both
> >
> > acpi_install_notify_handler()
> > and
> > acpi_remove_notify_handler()
> >
> > If we supported both ACPI notifications and non-ACPI notifications
> > all consumers would have to have support to register and use both types.
>
> Why would you want to support ACPI notifications and non-ACPI
> notifications? All you need is wbrf notification.
>
> The new wbrf.c should implement wbrf_install_notify_handler() and
> wbrf_remove_notify_handler().
>
> As to where to put wbrf.c? I guess either drivers/base/ or
> drivers/wbrf/. Maybe ask GregKH?

Not sure it should even be called WBRF at that point, but hey :)

Honestly I'm not sure though we need this complexity right now? I mean,
it'd be really easy to replace the calls in mac80211 with some other
more generalised calls in the future?

You need some really deep platform/hardware level knowledge and
involvement to do this, so I don't think it's something that someone
will come up with very easily for a DT-based platform...

If we do something with a notifier chain in the future, we can just
install one in the ACPI code too, and react indirectly rather than
calling from wifi to the ACPI directly.

johannes