Documentation/trace/events-power.rst

8   - Power state switch which reports events related to suspend (S-states),
9     cpuidle (C-states) and cpufreq (P-states)
10   - System clock related changes
11   - Power domains related changes and transitions
22 -----------------
24 A 'cpu' event class gathers the CPU-related events: cpuidle and
39 Note: the value of '-1' or '4294967295' for state means an exit from the current state,
41 enters the idle state 4, while trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id())
42 means that the system exits the previous idle state.
46 correctly draw the states diagrams and to calculate accurate statistics etc.
64 The power domain events are used for power domains transitions
69 The first parameter gives the power domain name (e.g. "mpu_pwrdm").
70 The second parameter is the power domain target state.