From: Rafael J. Wysocki Date: Tue, 11 Mar 2008 23:57:22 +0000 (+0100) Subject: PM: Handle device registrations during suspend/resume X-Git-Tag: v2.6.26-rc1~1126^2~17 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=58aca23226a19983571bd3b65167521fc64f5869;p=pandora-kernel.git 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 Acked-by: Pavel Machek Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed