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PM / doc: Update device documentation for devices in IRQ-safe PM domains 

Update documentation to reflect the changes made to support IRQ safe PM
domains.

Suggested-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Lina Iyer 2016-10-24 14:38:47 -07:00 committed by Rafael J. Wysocki
parent d716f4798f
commit 411bf2a8db
1 changed files with 13 additions and 1 deletions
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14
Documentation/power/devices.txt
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@ -607,7 +607,9 @@ individually. Instead, a set of devices sharing a power resource can be put
into a low-power state together at the same time by turning off the shared
power resource. Of course, they also need to be put into the full-power state
together, by turning the shared power resource on. A set of devices with this
property is often referred to as a power domain.
property is often referred to as a power domain. A power domain may also be
nested inside another power domain. The nested domain is referred to as the
sub-domain of the parent domain.
Support for power domains is provided through the pm_domain field of struct
device. This field is a pointer to an object of type struct dev_pm_domain,
@ -629,6 +631,16 @@ support for power domains into subsystem-level callbacks, for example by
modifying the platform bus type. Other platforms need not implement it or take
it into account in any way.
Devices may be defined as IRQ-safe which indicates to the PM core that their
runtime PM callbacks may be invoked with disabled interrupts (see
Documentation/power/runtime_pm.txt for more information). If an IRQ-safe
device belongs to a PM domain, the runtime PM of the domain will be
disallowed, unless the domain itself is defined as IRQ-safe. However, it
makes sense to define a PM domain as IRQ-safe only if all the devices in it
are IRQ-safe. Moreover, if an IRQ-safe domain has a parent domain, the runtime
PM of the parent is only allowed if the parent itself is IRQ-safe too with the
additional restriction that all child domains of an IRQ-safe parent must also
be IRQ-safe.
Device Low Power (suspend) States
---------------------------------