Intel P-State Driver Ready To Take On Alder Lake Hybrid Processors

Headlining the power management updates for the Linux 5.14 merge window is the Intel P-State CPU frequency scaling driver now being adapted to handle hybrid processors.

As noted last month, P-State has begun preparations for Alder Lake with this driver needing to be reworked to deal with the concept of Intel CPUs having a mix of energy efficient and high performance CPU cores. In particular, Intel 12th Gen "Alder Lake" processors to feature a mix of Golden Cove cores for performance and Gracemont cores when needing energy efficiency.

P-State will now use abstract performance units within the hardware P-States (HWP) interface for its frequency scaling of hybrid processors. This initial support is in place and will be interesting to see how it works out once Alder Lake processors begin appearing later in the year.

The Linux 5.14 power management code also now supports Intel P-State no-HWP mode for Icelake servers and Comet Lake desktops, the intel_idle driver will now use special C6 idle parameters when package C-states are disabled, and a variety of other improvements.

More details on the power management changes for this next kernel version via this pull request.

The ACPI updates were also submitted on Tuesday for Linux 5.14. On that front one of the interesting changes this cycle is the ACPI Platform Runtime Mechanism support in its initial form.