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authorMing Lei <ming.lei@canonical.com>2011-10-09 11:40:25 +0800
committerRafael J. Wysocki <rjw@sisk.pl>2011-10-10 23:37:23 +0200
commit2fb242adcaab5defa2f208775ac4f181ac998fdd (patch)
tree2ca3dc1f23849a8f1d44d730177a1ef3e436b087 /Documentation/power
parent2a5306cc5f383b0e7414c75e458111afd4a563a4 (diff)
PM / Runtime: Update document about callbacks
Support for device power domains has been introduced in commit 9659cc0678b954f187290c6e8b247a673c5d37e1 (PM: Make system-wide PM and runtime PM treat subsystems consistently), also power domain callbacks will take precedence over subsystem ones from commit 4d27e9dcff00a6425d779b065ec8892e4f391661(PM: Make power domain callbacks take precedence over subsystem ones). So update part of "Device Runtime PM Callbacks" in Documentation/power/runtime_pm.txt. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'Documentation/power')
-rw-r--r--Documentation/power/runtime_pm.txt19
1 files changed, 12 insertions, 7 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 1750740b17e8..f670836f8e5f 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