Re: HP Omnibook Ultra Flip 14 - power profiles

["Kurt Borja" <kuurtb@gmail.com>]

On Fri Jun 27, 2025 at 5:49 PM -03, Benjamin Hasselgren-Hallén wrote:
> Hi Kurt,
>
> I do not experience the same error messages as in the bug report - no error message at all. It respons to changing power profile without any errors.
> I also tried 6.12 but same behaviour as 6.15.3 (just getting some gpu glitches - problably because of Lunar Lake).

Can you paste the output of `cat /sys/firmware/acpi/platform_profile` on
Linux v6.12?

>
> I am trying to understand how power profiles work - I guess on a high level it's controlled by uefi and the profile is set by the OS? Or is it more complicated than that? 

Yes, as quick overview. Power profiles are usually a capability of
individual devices. Drivers of these devices expose this profiles to
userspace through some predefined interfaces. Then your DE enviroment
exposes this to you.

KDE and Gnome use power-profiles-daemon. This program controlls mainly
two kernel interfaces: CPUFreq and platform-profile (there may be more).

You can read about CPUFreq here [1], although I don't know much about
it. The platform-profile interface may be used by any platform driver -
in your case this is the hp-wmi driver.

This driver exposes some firmware defined profiles to sysfs trough the
following paths.

	/sys/firmware/acpi/
	/sys/class/platform-profile/

You won't find the latter in the Linux LTS version though. You will find
documentation on these paths here [2] and [3] respectively.

PD: Please, avoid top-posting in kernel mailing lists, interleaved style
is very much preferred [4].


[1] https://docs.kernel.org/admin-guide/pm/cpufreq.html
[2] https://docs.kernel.org/admin-guide/abi-testing-files.html#abi-file-testing-sysfs-platform-profile
[3] https://docs.kernel.org/admin-guide/abi-testing-files.html#abi-file-testing-sysfs-class-platform-profile
[4] https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

-- 
 ~ Kurt