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-rw-r--r--Documentation/power/runtime_pm.txt24
1 files changed, 15 insertions, 9 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 4ce5450ab6e..0e856088db7 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -43,13 +43,18 @@ struct dev_pm_ops {
...
};
-The ->runtime_suspend(), ->runtime_resume() and ->runtime_idle() callbacks are
-executed by the PM core for either the device type, or the class (if the device
-type's struct dev_pm_ops object does not exist), or the bus type (if the
-device type's and class' struct dev_pm_ops objects do not exist) of the given
-device (this allows device types to override callbacks provided by bus types or
-classes if necessary). The bus type, device type and class callbacks are
-referred to as subsystem-level callbacks in what follows.
+The ->runtime_suspend(), ->runtime_resume() and ->runtime_idle() callbacks
+are executed by the PM core for either the power domain, or the device type
+(if the device power domain's struct dev_pm_ops does not exist), or the class
+(if the device power domain's and type's struct dev_pm_ops object does not
+exist), or the bus type (if the device power domain's, type's and class'
+struct dev_pm_ops objects do not exist) of the given device, so the priority
+order of callbacks from high to low is that power domain callbacks, device
+type callbacks, class callbacks and bus type callbacks, and the high priority
+one will take precedence over low priority one. The bus type, device type and
+class callbacks are referred to as subsystem-level callbacks in what follows,
+and generally speaking, the power domain callbacks are used for representing
+power domains within a SoC.
By default, the callbacks are always invoked in process context with interrupts
enabled. However, subsystems can use the pm_runtime_irq_safe() helper function
@@ -431,8 +436,7 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h:
void pm_runtime_irq_safe(struct device *dev);
- set the power.irq_safe flag for the device, causing the runtime-PM
- suspend and resume callbacks (but not the idle callback) to be invoked
- with interrupts disabled
+ callbacks to be invoked with interrupts off
void pm_runtime_mark_last_busy(struct device *dev);
- set the power.last_busy field to the current time
@@ -478,12 +482,14 @@ pm_runtime_autosuspend_expiration()
If pm_runtime_irq_safe() has been called for a device then the following helper
functions may also be used in interrupt context:
+pm_runtime_idle()
pm_runtime_suspend()
pm_runtime_autosuspend()
pm_runtime_resume()
pm_runtime_get_sync()
pm_runtime_put_sync()
pm_runtime_put_sync_suspend()
+pm_runtime_put_sync_autosuspend()
5. Runtime PM Initialization, Device Probing and Removal