Linux 5.15 Power Management Changes Merged

Written by Michael Larabel in Hardware on 1 September 2021 at 05:55 AM EDT. Add A Comment
The ACPI and power management changes have landed for the Linux 5.15 merge window.

As usual, Intel's Rafael Wysocki punctually submitted all his new feature pull requests for the new merge window. This time around though the power management changes aren't particularly exciting. No exciting changes around new hardware support or the like... But there are a few changes worth mentioning:

- Power Limit 4 support for Intel next-gen Alder Lake hybrid processors was added to the Intel RAPL PowerCap driver.

- Intel P-State now supports hardware p-states (HWP) guaranteed performance change notifications around the HWP ratio changing as a result of changes to the power/thermal limits. This can be brought on by changing the TDP or altering the Intel Speed Select profile.

- Addressing of PCI device power management issues.

The full list of power management changes for Linux 5.15 can be found via this pull request.

Meanwhile the ACPI pull request updates the ACPICA code against upstream, adds some bits around LoongArch, some improvements to the platform profile code, and other clean-ups and enhancements.
Related News
About The Author
Michael Larabel

Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via

Popular News This Week