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Commit 8fd2910e authored by Krzysztof Kozlowski's avatar Krzysztof Kozlowski Committed by Rafael J. Wysocki
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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: default avatarKrzysztof Kozlowski <krzk@kernel.org>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 9735a227

Documentation/power/runtime_pm.txt

+4 −0
Original line number Original line Diff line number Diff line
@@ -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

but also it allows of more flexibility in the handling of devices during the

removal of their drivers.

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

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

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,

attribute to "on", which causes pm_runtime_forbid() to be called.  In principle,