APPLIED[M]: [SRU] [L/M] [PATCH 0/1] Fix ACPI TAD on some Intel based systems

[Andrea Righi]

On Wed, Aug 23, 2023 at 04:35:41PM +0800, Kai-Heng Feng wrote:
> BugLink: https://bugs.launchpad.net/bugs/2032767
> 
> [Impact]
> ACPI TAD doesn't really work on several systems. When accessing TAD
> interface via sysfs, like setting/getting realtime, it also causes
> errors:
> [  478.255453] ACPI Error: No handler for Region [RTCM] (00000000a8d2dd39) [SystemCMOS] (20230331/evregion-130)
> [  478.255458] ACPI Error: Region SystemCMOS (ID=5) has no handler (20230331/exfldio-261)
> [  478.255461] Initialized Local Variables for Method [_GRT]:
> [  478.255461]   Local1: 00000000f182542c <Obj>           Integer 0000000000000000
> [  478.255464] No Arguments are initialized for method [_GRT]
> [  478.255465] ACPI Error: Aborting method \_SB.AWAC._GRT due to previous error (AE_NOT_EXIST) (20230331/psparse-529)
> 
> [Fix]
> Let the driver to install a handler for its SystemCMOS region.
> The spec on whether certain devices can use SystemCMOS or not is quite
> vague, so follow the de facto implementation, Windows :)
> 
> [Test]
> Once the patch is applied, setting and getting realtime through TAD
> sysfs work, and there's no more error in dmesg.
> 
> [Where problems could occur]
> Now ACPI TAD driver also depends on ACPI RTC driver, so the memory usage
> will go up slightly.

Applied to mantic/linux.

Thanks,
-Andrea