summaryrefslogtreecommitdiffstats
path: root/kernel/Documentation/power/devices.txt
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/Documentation/power/devices.txt')
-rw-r--r--kernel/Documentation/power/devices.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/Documentation/power/devices.txt b/kernel/Documentation/power/devices.txt
index d172bce0f..8ba6625fd 100644
--- a/kernel/Documentation/power/devices.txt
+++ b/kernel/Documentation/power/devices.txt
@@ -341,6 +341,13 @@ the phases are:
and is entirely responsible for bringing the device back to the
functional state as appropriate.
+ Note that this direct-complete procedure applies even if the device is
+ disabled for runtime PM; only the runtime-PM status matters. It follows
+ that if a device has system-sleep callbacks but does not support runtime
+ PM, then its prepare callback must never return a positive value. This
+ is because all devices are initially set to runtime-suspended with
+ runtime PM disabled.
+
2. The suspend methods should quiesce the device to stop it from performing
I/O. They also may save the device registers and put it into the
appropriate low-power state, depending on the bus type the device is on,