Commit e358bad7 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki

PM / Runtime: Improve documentation of enable, disable and barrier

The runtime PM documentation in Documentation/power/runtime_pm.txt
doesn't say that pm_runtime_enable() and pm_runtime_disable() work by
operating on power.disable_depth, which is wrong, because the
possibility of nesting disables doesn't follow from the description
of these functions.  Also, there is no description of
pm_runtime_barrier() at all in the document, which is confusing.
Improve the documentation by fixing those issues.
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent 1e2ef05b
......@@ -369,17 +369,27 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
pm_runtime_autosuspend(dev) and return its result
void pm_runtime_enable(struct device *dev);
- enable the run-time PM helper functions to run the device bus type's
run-time PM callbacks described in Section 2
- decrement the device's 'power.disable_depth' field; if that field is equal
to zero, the run-time PM helper functions can execute subsystem-level
callbacks described in Section 2 for the device
int pm_runtime_disable(struct device *dev);
- prevent the run-time PM helper functions from running subsystem-level
run-time PM callbacks for the device, make sure that all of the pending
- increment the device's 'power.disable_depth' field (if the value of that
field was previously zero, this prevents subsystem-level runtime PM
callbacks from being run for the device), make sure that all of the pending
run-time PM operations on the device are either completed or canceled;
returns 1 if there was a resume request pending and it was necessary to
execute the subsystem-level resume callback for the device to satisfy that
request, otherwise 0 is returned
int pm_runtime_barrier(struct device *dev);
- check if there's a resume request pending for the device and resume it
(synchronously) in that case, cancel any other pending runtime PM requests
regarding it and wait for all runtime PM operations on it in progress to
complete; returns 1 if there was a resume request pending and it was
necessary to execute the subsystem-level resume callback for the device to
satisfy that request, otherwise 0 is returned
void pm_suspend_ignore_children(struct device *dev, bool enable);
- set/unset the power.ignore_children flag of the device
......
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