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

Signed-off-by: Lina Iyer <redacted>
Acked-by: Ulf Hansson <redacted>
---
 Documentation/power/devices.txt | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt
index 8ba6625..0401b53 100644
--- a/Documentation/power/devices.txt
+++ b/Documentation/power/devices.txt

@@ -607,7 +607,14 @@ 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.
+
+Devices and PM domains may be defined as IRQ-safe, if they can be powered
+on/off even when the IRQs are disabled. An IRQ-safe device in a domain will
+disallow power management on the domain, unless the domain is also defined as
+IRQ-safe. The restriction this framework imposes on the parent domain of an
+IRQ-safe domain is that it must also be defined as IRQ-safe.