[PATCH v4 9/9] PM / doc: Update device documentation for devices in IRQ safe PM domains

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
---
 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 8ba6625..73ddea3 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
 ---------------------------------
-- 
2.7.4

--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux