From 411bf2a8db76d7ed6f710df77121e5113ee8fe64 Mon Sep 17 00:00:00 2001 From: Lina Iyer Date: Mon, 24 Oct 2016 14:38:47 -0700 Subject: [PATCH] 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 Signed-off-by: Lina Iyer Signed-off-by: Rafael J. Wysocki --- Documentation/power/devices.txt | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 8ba6625fdd63..73ddea39a9ce 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -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 ---------------------------------