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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-06-28 13:01:40 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-06-28 13:01:40 +0200 |
| commit | e52cff8bdd4a30c40a7f65c7ea8f1f425f8a15eb (patch) | |
| tree | 1729332ebab51bb560ca64effe46cdab38ab537f /Documentation/power/runtime_pm.txt | |
| parent | 405a1086bdd091d2d55db0ac905cd6332b35cec1 (diff) | |
| parent | f5ce1572109049b90484e2bb44927cb6034c5eb1 (diff) | |
| download | linux-e52cff8bdd4a30c40a7f65c7ea8f1f425f8a15eb.tar.gz linux-e52cff8bdd4a30c40a7f65c7ea8f1f425f8a15eb.tar.bz2 linux-e52cff8bdd4a30c40a7f65c7ea8f1f425f8a15eb.zip | |
Merge branch 'pm-assorted'
* pm-assorted:
PM / QoS: Add pm_qos and dev_pm_qos to events-power.txt
PM / QoS: Add dev_pm_qos_request tracepoints
PM / QoS: Add pm_qos_request tracepoints
PM / QoS: Add pm_qos_update_target/flags tracepoints
PM / QoS: Update Documentation/power/pm_qos_interface.txt
PM / Sleep: Print last wakeup source on failed wakeup_count write
PM / QoS: correct the valid range of pm_qos_class
PM / wakeup: Adjust messaging for wake events during suspend
PM / Runtime: Update .runtime_idle() callback documentation
PM / Runtime: Rework the "runtime idle" helper routine
PM / Hibernate: print physical addresses consistently with other parts of kernel
Diffstat (limited to 'Documentation/power/runtime_pm.txt')
| -rw-r--r-- | Documentation/power/runtime_pm.txt | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt index 6c9f5d9aa115..71d8fe4e75d3 100644 --- a/Documentation/power/runtime_pm.txt +++ b/Documentation/power/runtime_pm.txt @@ -144,8 +144,12 @@ The action performed by the idle callback is totally dependent on the subsystem (or driver) in question, but the expected and recommended action is to check if the device can be suspended (i.e. if all of the conditions necessary for suspending the device are satisfied) and to queue up a suspend request for the -device in that case. The value returned by this callback is ignored by the PM -core. +device in that case. If there is no idle callback, or if the callback returns +0, then the PM core will attempt to carry out a runtime suspend of the device; +in essence, it will call pm_runtime_suspend() directly. To prevent this (for +example, if the callback routine has started a delayed suspend), the routine +should return a non-zero value. Negative error return codes are ignored by the +PM core. The helper functions provided by the PM core, described in Section 4, guarantee that the following constraints are met with respect to runtime PM callbacks for @@ -301,9 +305,10 @@ drivers/base/power/runtime.c and include/linux/pm_runtime.h: removing the device from device hierarchy int pm_runtime_idle(struct device *dev); - - execute the subsystem-level idle callback for the device; returns 0 on - success or error code on failure, where -EINPROGRESS means that - ->runtime_idle() is already being executed + - execute the subsystem-level idle callback for the device; returns an + error code on failure, where -EINPROGRESS means that ->runtime_idle() is + already being executed; if there is no callback or the callback returns 0 + then run pm_runtime_suspend(dev) and return its result int pm_runtime_suspend(struct device *dev); - execute the subsystem-level suspend callback for the device; returns 0 on @@ -660,11 +665,6 @@ Subsystems may wish to conserve code space by using the set of generic power management callbacks provided by the PM core, defined in driver/base/power/generic_ops.c: - int pm_generic_runtime_idle(struct device *dev); - - invoke the ->runtime_idle() callback provided by the driver of this - device, if defined, and call pm_runtime_suspend() for this device if the - return value is 0 or the callback is not defined - int pm_generic_runtime_suspend(struct device *dev); - invoke the ->runtime_suspend() callback provided by the driver of this device and return its result, or return -EINVAL if not defined |