PM / Runtime: Automatically retry failed autosuspends
authorAlan Stern <stern@rowland.harvard.edu>
Thu, 3 Nov 2011 22:39:18 +0000 (23:39 +0100)
committerRafael J. Wysocki <rjw@sisk.pl>
Fri, 4 Nov 2011 21:28:14 +0000 (22:28 +0100)
commit886486b792e4f6f96d4fbe8ec5bf20811cab7d6a
tree1c638e14492c16f8f69ca71fa93b2d81d8e4eeb6
parent6513fd6972f725291ee8ce62c7a39fb8a6c7391e
PM / Runtime: Automatically retry failed autosuspends

Originally, the runtime PM core would send an idle notification
whenever a suspend attempt failed.  The idle callback routine could
then schedule a delayed suspend for some time later.

However this behavior was changed by commit
f71648d73c1650b8b4aceb3856bebbde6daa3b86 (PM / Runtime: Remove idle
notification after failing suspend).  No notifications were sent, and
there was no clear mechanism to retry failed suspends.

This caused problems for the usbhid driver, because it fails
autosuspend attempts as long as a key is being held down.  Therefore
this patch (as1492) adds a mechanism for retrying failed
autosuspends.  If the callback routine updates the last_busy field so
that the next autosuspend expiration time is in the future, the
autosuspend will automatically be rescheduled.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Henrik Rydberg <rydberg@euromail.se>
Cc: <stable@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Documentation/power/runtime_pm.txt
drivers/base/power/runtime.c