PM / Runtime: Update document about callbacks

Support for device power domains has been introduced in
commit 9659cc0678 (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>
This commit is contained in:
Ming Lei 2011-10-09 11:40:25 +08:00 committed by Rafael J. Wysocki
parent 2a5306cc5f
commit 2fb242adca
1 changed files with 12 additions and 7 deletions

View File

@ -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