AMD P-State Fixes, Fixing s2idle For Some Rembrandt Laptops Lead ACPI/PM For Linux 6.1

The ACPI, power management, and thermal subsystem pull requests have been sent in for the in-development Linux 6.1 kernel.

The power management changes this cycle aren't too particularly exciting but there is some continued code churn around the amd_pstate driver. When it comes to the AMD P-State driver, there are a number of fixes. The AMD P-State driver fixes involve reading the wrong lowest performance state, mapping the desired perf into the p-state scope for the powersave governor, updating the P-State frequency transition delay time, and fixing the initial highest perf value. We'll see how well these fixes work out for AMD P-State with Linux 6.1. In case you missed it, see this morning's AMD P-State benchmarks on Rembrandt with Linux 6.0.

AMD engineers have also been working on the AMD P-State EPP driver but that sadly isn't part of this Linux 6.1 feature material.

On the Intel P-State driver side, there is Tiger Lake support for when operating in no-HWP (Hardware P-States) mode. Some of the other power management work includes support for the Tegra239 SoC, Intel Alder Lake N support within the Intel_Idle driver, and a variety of bug fixes.

The full list of power management patches for the Linux 6.1 merge window can be found via this pull request by maintainer Rafael Wysocki of Intel.

Rafael also submitted the ACPI updates for Linux 6.1. Notable here is fixing suspend-to-idle (s2idle) on more AMD Rembrandt laptops. As of right now the newly-fixed AMD Rembrandt laptops for s2idle support include the:

- ASUS ROG Flow X16 GV601
- ASUS ROG Flow X13 GV301
- Lenovo Slim 7 Pro 14ARH7
- ASUS ROG Zephyrus G14
- ASUS TUF Gaming A17 FA707RE

This stems from the work covered last month in AMD Prepares s2idle Fixes For AMD Ryzen 6000 Series Powered ASUS Laptops and More AMD Ryzen Laptops See Suspend-To-Idle Fix. If you think your laptop may be dealing with firmware issues around suspend-to-idle, the acpi.prefer_microsoft_guid=1 kernel parameter is added with Linux 6.1 for easily applying this behavior to other laptop models for testing.

ASUS ROG Flow x16

It's great seeing this AMD Ryzen client platform fixes coming directly from AMD engineers with the company ramping up their Linux client efforts in recent years compared to the past while still not quite to the level of contributions and early enablement as generally seen by Intel.

There are also a variety of fixes and DT changes as part of the thermal updates sent in as well today by Rafael.