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authorRafael J. Wysocki <rjw@sisk.pl>2008-03-12 00:57:22 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-19 19:10:24 -0700
commit58aca23226a19983571bd3b65167521fc64f5869 (patch)
tree1fd3f54ce5f18dc972b77970289a27a4e4a39bee /include/linux/pm.h
parent6bcf19d02a5d7e627fa054f2f10e0a8d830df326 (diff)
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>
Diffstat (limited to 'include/linux/pm.h')
-rw-r--r--include/linux/pm.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 015b735811b..e6b9f29e27d 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -183,6 +183,7 @@ typedef struct pm_message {
struct dev_pm_info {
pm_message_t power_state;
unsigned can_wakeup:1;
+ bool sleeping:1; /* Owned by the PM core */
#ifdef CONFIG_PM_SLEEP
unsigned should_wakeup:1;
struct list_head entry;