Not yet ready, Linux 6.2will not incorporate AMD P-State Linux-driven EPP functionality

CTOnews.com December 13, Linux will not incorporate the EPP functionality of the AMD P-State Linux driver during the Linux Kernel 6.2 merge window. The EPP driver uses ACPI CPPC energy preference performance information to control the power of the CPU, making the processor more efficient and improving performance.

CTOnews.com learned that AMD's EPP driver works by using a P-State CPU frequency driver, extending its implementation through ACPI CPP EPP data, and guiding hardware decisions between energy efficiency and performance. The firmware that produces a low power level will estimate the frequency of the runtime and then let EPP indicate the processor core frequency of the system.

Many users want Linux 6.2 to incorporate this EPP feature, but Rafael Wysocki from Intel, the maintainer of the Linux kernel ACPI and power management, believes that the EPP-related code is not fully prepared.

He wrote in the kernel mailing list:

To be honest, I don't think this job is ready for 6.2.

The number of patches in this series seems to change frequently, and there is an active discussion around specific patches.

Therefore, I won't consider applying 6.2-rc1 until it comes out.

The AMD engineer is now going to modify the patch series to make some additional fixes and documentation for the AMD P-State EPP schema.