linux-kernel - Re: [PATCH 0/3] Add support for hidden choices to platform

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Message-ID: <CAFqHKTkCnSxUMoR76vibC394wkgdU1hQLrt0TAAyya95QOxJWQ@mail.gmail.com>
Date: Fri, 28 Feb 2025 12:38:16 -0800
From: Derek John Clark <derekjohn.clark@...il.com>
To: Mario Limonciello <superm1@...nel.org>
Cc: Shyam Sundar S K <Shyam-sundar.S-k@....com>, "Rafael J . Wysocki" <rafael@...nel.org>, 
	Hans de Goede <hdegoede@...hat.com>, Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, 
	"Luke D . Jones" <luke@...nes.dev>, Mark Pearson <mpearson-lenovo@...ebb.ca>, 
	"open list:AMD PMF DRIVER" <platform-driver-x86@...r.kernel.org>, 
	open list <linux-kernel@...r.kernel.org>, 
	"open list:ACPI" <linux-acpi@...r.kernel.org>, Antheas Kapenekakis <lkml@...heas.dev>, me@...egospodneti.ch, 
	Denis Benato <benato.denis96@...il.com>, Mario Limonciello <mario.limonciello@....com>
Subject: Re: [PATCH 0/3] Add support for hidden choices to platform_profile

On Fri, Feb 28, 2025 at 9:02 AM Mario Limonciello <superm1@...nel.org> wrote:
>
> From: Mario Limonciello <mario.limonciello@....com>
>
> When two drivers provide platform profile handlers but use different
> strings to mean (essentially) the same thing the legacy interface won't
> export them because it only shows profiles common to multiple drivers.
>
> This causes an unexpected behavior to people who have upgraded from an
> earlier kernel because if multiple drivers have bound platform profile
> handlers they might not be able to access profiles they were expecting.
>
> Introduce a concept of a "hidden choice" that drivers can register and
> the platform profile handler code will utilize when using the legacy
> interface.
>
> There have been some other attempts at solving this issue in other ways.
> This serves as an alternative to those attempts.
>
> Link: https://lore.kernel.org/platform-driver-x86/e64b771e-3255-42ad-9257-5b8fc6c24ac9@gmx.de/T/#t
> Link: https://lore.kernel.org/platform-driver-x86/CAGwozwF-WVEgiAbWbRCiUaXf=BVa3KqmMJfs06trdMQHpTGmjQ@mail.gmail.com/T/#m2f3929e2d4f73cc0eedd14738170dad45232fd18
> Cc: Antheas Kapenekakis <lkml@...heas.dev>
> Cc: "Luke D. Jones" <luke@...nes.dev>
>
> Mario Limonciello (3):
>   ACPI: platform_profile: Add support for hidden choices
>   platform/x86/amd: pmf: Add 'quiet' to hidden choices
>   platform/x86/amd: pmf: Add balanced-performance to hidden choices
>
>  drivers/acpi/platform_profile.c    | 94 +++++++++++++++++++++++-------
>  drivers/platform/x86/amd/pmf/sps.c | 11 ++++
>  include/linux/platform_profile.h   |  3 +
>  3 files changed, 87 insertions(+), 21 deletions(-)
>
> --
> 2.43.0
>

Everything seems to be working as intended. I applied these patches on
top of my lenovo-wmi series modified to always show
balanced-performance and with quiet as the lowest profile. Testing was
done on the Legion Go.
Results:

$ cat /sys/firmware/acpi/platform_profile_choices
quiet balanced balanced-performance performance
$ for f in *; do cat $f/name; cat $f/choices; done;
lenovo-wmi-gamezone
quiet balanced balanced-performance performance custom
amd-pmf
low-power balanced performance
$ echo quiet | sudo tee /sys/firmware/acpi/platform_profile
quiet
$ for f in *; do cat $f/name; cat $f/profile; done;
lenovo-wmi-gamezone
quiet
amd-pmf
quiet
$ echo balanced-performance | sudo tee /sys/firmware/acpi/platform_profile
balanced-performance
$ for f in *; do cat $f/name; cat $f/profile; done;
lenovo-wmi-gamezone
balanced-performance
amd-pmf
balanced-performance
$ echo low-power | sudo tee /sys/firmware/acpi/platform_profile
low-power
tee: /sys/firmware/acpi/platform_profile: Operation not supported
$ for f in *; do cat $f/name; cat $f/profile; done;
lenovo-wmi-gamezone
balanced-performance
amd-pmf
balanced-performance

Tested-by: Derek J. Clark <derekjohn.clark@...il.com>