Re: [PATCH v1] platform/x86: ideapad-laptop: Fix resume behavior for Lenovo Yoga 15ILL9

[Gergo Koteles]

Hey Jakob,

On Tue, 2026-01-06 at 23:09 +0100, Jakob wrote:
> On the Lenovo Yoga Slim 7 15ILL9, the Embedded Controller fails to restore
> its state after resuming from suspend. This results in the cooling fans
> remaining stopped (causing overheating), the keyboard backlight and
> brightness keys becoming unresponsive, and the power button LED continuing
> to pulse as if still suspended.
> 
> Testing shows that invoking the UPHK method with command 0x09 properly
> resets the EC state. This single command restores fan control, fixes the
> keyboard backlight and brightness keys and corrects the power LED behavior.
> 

Based on the ACPI dump https://0x0.st/Ku-I.tar.gz from
https://bbs.archlinux.org/viewtopic.php?id=306675 , it appears that
this is a new feature (Win11 22H2) in Microsoft Modern Standby firmware
notifications (11e00d56-ce64-47ce-837b-1f898f9aa461).

If ((Arg0 == ToUUID ("11e00d56-ce64-47ce-837b-1f898f9aa461") /* Unknown
UUID */))
{
   If (CondRefOf (\_SB.PC00.LPCB.EC0.UPHK))
   {
     ^^PC00.LPCB.EC0.UPHK (ToInteger (Arg2))
   }

Described here:


https://learn.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-firmware-notifications#turn-on-display-notification-function-9

I think instead of this driver, this notification function can be added
to the s2idle module (/drivers/acpi/x86/s2idle.c) without a quirk.


Best regards,
Gergo Koteles