diff options
authorKrzysztof Kozlowski <krzk@kernel.org>2016-04-03 12:23:07 +0900
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-04-05 03:46:59 +0200
commit8fd2910e31155d8562180cc8580bc27e3be4f4bf (patch)
parent9735a22799b9214d17d3c231fe377fc852f042e9 (diff)
PM / runtime: Document steps for device removal
Put a reminder that during device removal drivers should revert all PM runtime changes from the probe. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 7328cf85236c..1fd1fbe9ce95 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -586,6 +586,10 @@ drivers to make their ->remove() callbacks avoid races with runtime PM directly,
but also it allows of more flexibility in the handling of devices during the
removal of their drivers.
+Drivers in ->remove() callback should undo the runtime PM changes done
+in ->probe(). Usually this means calling pm_runtime_disable(),
+pm_runtime_dont_use_autosuspend() etc.
The user space can effectively disallow the driver of the device to power manage
it at run time by changing the value of its /sys/devices/.../power/control
attribute to "on", which causes pm_runtime_forbid() to be called. In principle,