3.2.2.11.3. CPUIdle

Overview

The cpuidle framework consists of two key components:

A governor that decides the target C-state of the system. A driver that implements the functions to transition to target C-state. The idle loop is executed when the Linux scheduler has no thread to run. When the idle loop is executed, current ‘governor’ is called to decide the target C-state. Governor decides whether to continue in current state/ transition to a different state. Current ‘driver’ is called to transition to the selected state.

The A53 cores on AM62Ax currently support only the Wait for Interrupt (WFI) C-state. This state gets enabled by default in the CPUIdle driver without requiring any additional DT configuration.