linux-kernel - Re: [PATCH 0/3] ACPI: platform_profile: fix legacy sysfs with multiple handlers

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Message-ID: 
 <CAGwozwEkGDfhUoCSM6eA-1QN3-pCixT-YVPBNY4bLUZYxvff8Q@mail.gmail.com>
Date: Wed, 26 Feb 2025 23:15:16 +0100
From: Antheas Kapenekakis <lkml@...heas.dev>
To: "Rafael J. Wysocki" <rafael@...nel.org>
Cc: Armin Wolf <W_Armin@....de>, Luke Jones <luke@...nes.dev>,
	Mark Pearson <mpearson-lenovo@...ebb.ca>,
	"Limonciello, Mario" <mario.limonciello@....com>,
	Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	Len Brown <lenb@...nel.org>,
 "linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
	linux-kernel@...r.kernel.org,
	"platform-driver-x86@...r.kernel.org" <platform-driver-x86@...r.kernel.org>,
 Hans de Goede <hdegoede@...hat.com>,
	me@...egospodneti.ch
Subject: Re: [PATCH 0/3] ACPI: platform_profile: fix legacy sysfs with
 multiple handlers

On Wed, 26 Feb 2025 at 21:04, Rafael J. Wysocki <rafael@...nel.org> wrote:
>
> Top-posting not welcome.

?

> On Wed, Feb 26, 2025 at 8:52 PM Antheas Kapenekakis <lkml@...heas.dev> wrote:
> > >
> > > What about adding "quiet" as a "hidden choice" to amd-pmf such that it
> > > would allow the test_bit(*bit, handler->choices) check in
> > > _store_class_profile() to pass, but it would not cause this "choice"
> > > to become visible in the new I/F (or when amd-pmf becomes the only
> > > platform-profile driver) and it would be aliased to "low-power"
> > > internally?
> >
> > This is what this patch series essentially does. It makes amd-pmf
> > accept all choices but only show its own in its own handler and when
> > it is the only option
>
> No, it does more than this.

I would say functionality-wise no. The patch could be minified further.

>  For instance, it is not necessary to do
> anything about PLATFORM_PROFILE_BALANCED_PERFORMANCE in it.

I do not see a difference between QUIET and BALANCED_PERFORMANCE, any
driver occluding either causes the same issue. Severity is debatably
lower on BP though.

> The structure of it is questionable either.  It really should be two
> patches, one modifying the ACPI platform-profile driver and the other
> changing amd-pmf on top of this.

Ack. I can spin it up as 2 patches.

> Moreover, I'm not entirely convinced that the "secondary" driver
> concept is needed to address the problem at hand.

Any suggestions on that front would be welcome. This is just the way I
came up with doing it.

Best,
Antheas