X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2Fpower%2Fruntime_pm.txt;h=4ce5450ab6e833cef372ef2755993353cae50935;hb=19b4a8d520a6e0176dd52aaa429261ad4fcaa545;hp=14dd3c6ad97ee852d0273a7a66c57b5ebe74b34b;hpb=0b576372e86c8e6bee01506651b21ec0fe8a1698;p=pandora-kernel.git diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 14dd3c6ad97e..0e856088db7c 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -43,22 +43,26 @@ 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 to tell the PM core that a device's ->runtime_suspend() and ->runtime_resume() -callbacks should be invoked in atomic context with interrupts disabled -(->runtime_idle() is still invoked the default way). This implies that these -callback routines must not block or sleep, but it also means that the -synchronous helper functions listed at the end of Section 4 can be used within -an interrupt handler or in an atomic context. +callbacks should be invoked in atomic context with interrupts disabled. +This implies that these callback routines must not block or sleep, but it also +means that the synchronous helper functions listed at the end of Section 4 can +be used within an interrupt handler or in an atomic context. The subsystem-level suspend callback is _entirely_ _responsible_ for handling the suspend of the device as appropriate, which may, but need not include @@ -432,8 +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 @@ -479,11 +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