x86 ACPI platform glue: Apple, Intel LPSS, CMOS RTC quirks, and Low-Power S0 idle
A collection of small x86-specific ACPI helpers that make modern PCs and Macs behave correctly under Linux. It covers Apple firmware quirks, Intel Low Power Subsystem (LPSS) enumeration on recent Intel laptops and tablets, CMOS real-time clock workarounds, and the Low Power S0 / Modern Standby suspend-to-idle path used by current Windows-class hardware.
recommendation
Worth keeping but documenting its scope, because this is not a single hardware driver but a mixed bucket of x86 ACPI quirks and platform glue. The code is still actively maintained, with substantive updates landing into 2024-2025 around suspend-to-idle and Intel LPSS, and it underpins Modern Standby behaviour on laptops being sold new today. Annotation would help future readers understand it is a heterogeneous support area rather than one self-contained driver.
repository signals
sources
- git.zx2c4.com
Directory has sustained upstream activity through 2024-2025, including LPSS, s2idle, and x86 quirk fixes; no removal/deprecation trend is visible.
- cateee.net
`drivers/acpi/x86/lpss.c` still maps current kernel support for Intel LPSS-related ACPI IDs and remains present through 6.19-rc/HEAD.
- cateee.net
Newer Intel LPSS ACPI-mode devices are also handled by `intel-lpss-acpi`, showing the area is still relevant upstream rather than obsolete.
- learn.microsoft.com
Low-power S0 idle (Modern Standby) is an increasing current-platform deployment class, supporting continued relevance of the directory's s2idle/LPS0 code.
- docs.kernel.org
Linux kernel docs describe Low Power S0 idle/LPIT on Intel platforms, indicating this power-management path is current platform functionality, not purely legacy.
codex reasoning notes (technical)
Local `exec_command` file inspection shows this directory is a mixed ACPI x86 helper/quirk area (`apple.c`, `cmos_rtc.c`, `lpss.c`, `s2idle.c`), not a single removable legacy driver. `exec_command` git log with safe.directory shows substantive non-treewide changes in 2024-2026, including 2026-02-12 and 2026-01 s2idle updates. URLs were obtained by `web.search_query`: zx2c4 log query for `drivers/acpi/x86` activity, LKDDb queries for LPSS coverage, and Microsoft/kernel-doc queries for Low Power S0 deployment context. Recommendation is `keep-annotate` because the directory is active and still needed, but it is a heterogeneous x86 ACPI support bucket with some legacy quirk content rather than a clean standalone hardware driver.