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

From: Mario Limonciello

Date: Tue Aug 11 2026 - 13:54:22 EST




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>

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

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