Add documentation for the device_pm_callback_{start, end} events
under the "Subsystem Trace Points: power" section.Signed-off-by: Yo-Jung (Leo) Lin <0xf...@gmail.com> --- Documentation/trace/events-power.rst | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/Documentation/trace/events-power.rst b/Documentation/trace/events-power.rst index f45bf11fa88d..7031954f7ed3 100644 --- a/Documentation/trace/events-power.rst +++ b/Documentation/trace/events-power.rst @@ -102,3 +102,30 @@ And, there are events used for CPU latency QoS add/update/remove request. pm_qos_remove_request "value=%d" The parameter is the value to be added/updated/removed. + +5. Device PM callback events +============================ +The device PM callback events are placed right before and after an invocation of +a device PM callback during a system-wide suspend/resume attempt. +:: + + device_pm_callback_start "%s %s, parent: %s, %s[%s]" + device_pm_callback_end "%s %s, err=%d" + +The first two parameters in both events are the same. They are: + + - The name of the driver. + - The device whose PM callbacks get called. + +For device_pm_callback_start, the rest of the parameters are: + + - The parent device of the device (if any). + - Level in the power management hierarchy the callback belongs to (e.g. power + domain, type, class, bus, driver). Some stages (e.g. early, late, noirq) + will also be explicitly mentioned in this string. + - The ongoing PM event. You may find definitions of those events in the + PM_EVENT_* macros in include/linux/pm.h + +For device_pm_callback_end, the only remaining parameter is: + + - The return value of the PM callback. -- 2.43.0
