Atomic cpufreq set operation using platform firmware interface on ARM


One Line Summary

How to achieve or make operations in OSPM atomic for CPU frequency scaling using platform firmware interface on ARM platforms ?


The schedutil governor supports fast frequency switching if that is supported by the cpufreq driver in use and possible for the given policy. Generally most of the traditional ARM platforms drive the PMIC to set OPP using slow bus like I2C. However, newer platforms have dedicated processor or atleast firmware to drive CPU OPP.

Since ARM SCMI also standardize the firmware interface, can we use it to provide fast switch mechanism on ARM platforms.

Presentation Materials



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    Sudeep works on Linux kernel’s power management code, cpuidle, cpufreq, and the ACPI subsystem. He works at ARM Ltd, Cambridge as a Linux Kernel Engineer mainly focusing on power management in Linux kernel, ACPI and other platform/power interfaces like PSCI, SCPI, SCMI,..etc. He has been contributing to the Linux kernel since 2012 and co-maintaining support for ARM Versatile Express development platforms.