Re: [PATCH] ACPI: OSI: Enable _OSI("Windows 2022") on HP OmniBook X Flip 16-ar0xxx

From: Mario Limonciello

Date: Tue Aug 11 2026 - 15:08:45 EST




On 8/11/26 13:45, David Del Sol wrote:
Thanks for looking into this Mario,
I'm not 100% sure of the root cause, and after dumping the
ACPI tables I know my original explanation was wrong: there's no
`_OSI("Windows 2022")` check anywhere in the DSDT or SSDTs.

It seemed like you were referencing a non-existent callback in your patch too. I don't know how that could have possibly compiled.


What I do know: the combo `acpi_osi=! acpi_osi="Windows 2022"` reliably
takes charging from ~0.2 W to 31-33 W. I'm isolating which half of the
command line actually does the work now (testing each half alone), and
I'll report back what I find, then update the bugzilla report with the
corrected story.

It's more likely that the 'acpi_osi=!' did something IMO.

What strings are in your BIOS? Have you looked at an acpidump yet?


David

On Tue, Aug 11, 2026 at 12:52 PM Mario Limonciello <mario.limonciello@xxxxxxx <mailto:mario.limonciello@xxxxxxx>> wrote:



On 8/11/26 12:48, David Del Sol wrote:
> Hi all,
>
> This fixes slow battery charging on the 2025 HP OmniBook X Flip
(AMD Ryzen
> AI 5 340, DMI board 8DA8): with a 65 W charger plugged in, the
battery
> charges at only ~0.2 W on Linux instead of the ~30 W Windows gets.
>
> The EC firmware only enables normal charging when the OS claims
> _OSI("Windows 2022"), and the DSDT/SSDT only check up to that string.
> Linux's default claimed OSI strings stop short of it, so the
fast-charging
> branch never runs. Adding acpi_osi=! acpi_osi="Windows 2022" to
the kernel
> cmdline restores 31-33 W - verified across multiple charge cycles on
> kernels 7.1.6 and 6.18.42-LTS.
>
> I checked with HP first: they declined in writing (warranty case
> #5163282638, supervisor email 2026-08-10), saying the firmware is
> "specifically manufactured and optimized for the Windows
operating system"
> and not supported for other OSes. A kernel-side quirk is
therefore the
> only fix path.
>
> The patch claims _OSI("Windows 2022") via acpi_osi_setup() with a DMI
> match scoped to board 8DA8 (same mechanism as
dmi_enable_osi_linux), so
> no other platform is affected. Full evidence - DSDT/SSDT strings,
EC RAM
> dumps, measurement logs - is on the bugzilla report below; happy
to add
> sibling boards as owners confirm.
>
> Thanks for looking,
> David
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=221866
<https://bugzilla.kernel.org/show_bug.cgi?id=221866> <https://
> bugzilla.kernel.org/show_bug.cgi?id=221866 <http://
bugzilla.kernel.org/show_bug.cgi?id=221866>>

Are you sure about your proposed root cause?  It has been enabled a
very
long time.

https://git.kernel.org/torvalds/c/dd067afe3f8cb <https://
git.kernel.org/torvalds/c/dd067afe3f8cb>