AMD P-State Linux Driver Gets Fixed Up For Threadripper 3000 Series CPUs

The AMD P-State CPU frequency scaling driver for improved thermal/power/performance behavior under Linux works for Zen 2 and newer systems where the platform exposes ACPI Collaborative Processor Performance Controls (CPPC) support. There's been a caveat though of the "amd_pstate" driver having issues for the Zen2-based Ryzen Threadripper 3000 series. With a newly-published set of patches, that issue should be resolved.

Since last November has been a bug report over the AMD P-State driver not loading for Threadripper 3000 series / TRX40 motherboards over lacking CPPC support even though CPPC and AMD P-State Preferred Core are enabled by the BIOS... The fix ended up being a one-liner that the AMD CPU model check needed to be expanded from 0x70 to 0x7f to instead 0x30 to 0x7f to catch all the Threadripper 3000 series processors.

That fix was part of 6 patches posted today to also provide other fixes/improvements to the AMD P-State driver. There is also a fix/quirk specific to the AMD EPYC 7K62 so it will work with the P-State driver.

If all goes well these "enhancements" will be found in the upcoming Linux v6.9 kernel or they may even be worked into fixes still for v6.8.