]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
PM: Handle device registrations during suspend/resume
authorRafael J. Wysocki <rjw@sisk.pl>
Tue, 11 Mar 2008 23:57:22 +0000 (00:57 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Sun, 20 Apr 2008 02:10:24 +0000 (19:10 -0700)
commit58aca23226a19983571bd3b65167521fc64f5869
tree1fd3f54ce5f18dc972b77970289a27a4e4a39bee
parent6bcf19d02a5d7e627fa054f2f10e0a8d830df326
PM: Handle device registrations during suspend/resume

Modify the PM core to protect its data structures, specifically the
dpm_active list, from being corrupted if a child of the currently
suspending device is registered concurrently with its ->suspend()
callback.  In that case, since the new device (the child) is added
to dpm_active after its parent, the PM core will attempt to
suspend it after the parent, which is wrong.

Introduce a new member of struct dev_pm_info, called 'sleeping',
and use it to check if the parent of the device being added to
dpm_active has been suspended, in which case the device registration
fails.  Also, use 'sleeping' for checking if the ordering of devices
on dpm_active is correct.

Introduce variable 'all_sleeping' that will be set to 'true' once all
devices have been suspended and make new device registrations fail
until 'all_sleeping' is reset to 'false', in order to avoid having
unsuspended devices around while the system is going into a sleep state.

Remove pm_sleep_rwsem which is not necessary any more.

Special thanks to Alan Stern for discussions and suggestions that
lead to the creation of this patch.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Documentation/power/devices.txt
drivers/base/core.c
drivers/base/power/main.c
drivers/base/power/power.h
include/linux/pm.h