Many ACPI Updates Head To The Linux 6.12 Kernel

Ahead of the expected Linux 6.11 stable release today and the Linux Kernel Maintainer Summit happening this coming week in Vienna, Intel engineer Rafael Wysocki submitted early the ACPI updates among the other areas of the kernel he oversees as part of the imminent Linux 6.12 merge window.

There's a lot on the ACPI side for Linux 6.12 that I'm covering the changes separately from all of the other Linux power management changes coming into this next kernel release. Among the ACPI feature material submitted for Linux 6.12 includes:

- Support for ACPI-based enumeration of interrupt controllers on RISC-V platforms.

- Completing the CXL 3.0 CXIMS structures support in the ACPICA code. CXL 3.0 CXIMS is for CXL XOR Interleave Math.

- Support for the Microsoft Windows 11 22H2 ACPI _OSI string.

- Preparations for ACPICA release 20240827.

- A new AMD "AMDI0015" platform device ID is added to the ACPI APD driver for AMD SoCs. Presumably AMDI0015 is for a new AMD Zen 5 mobile device ID. This change is needed to ensure correct clock settings for the I3C device.

- Enforcing native backlight handling for the Apple MacBookPro9,2 that is the Apple MacBook Pro Intel model from mid-2012.

- IRQ override quirks for the ASUS Vivobook Go E1404GAB and MECHREV GM7XG0M.

- An ASUS ROG M16 quirk to default to S3 sleep.

- Support for the ACPI CPPC code to allow setting the Energy Performance Preference (EPP) register in the Functional Fixed Hardware (FFH) address space. This is to overcome some ASUS AMD systems reporting not being able to change EPP values for power/performancr tuning. The workaround is making use of ACPI 6.2 to be declared in the FFH.

More details on the submitted ACPI changes for the Linux 6.12 merge window via this early pull request.