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authorRafael J. Wysocki <rjw@sisk.pl>2008-03-11 19:57:22 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-19 22:10:24 -0400
commit58aca23226a19983571bd3b65167521fc64f5869 (patch)
tree1fd3f54ce5f18dc972b77970289a27a4e4a39bee /drivers/base/power/power.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 'drivers/base/power/power.h')
-rw-r--r--drivers/base/power/power.h23
1 files changed, 3 insertions, 20 deletions
diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index e32d3bdb92c1..a6894f2a4b99 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -11,30 +11,13 @@ static inline struct device *to_device(struct list_head *entry)
11 return container_of(entry, struct device, power.entry); 11 return container_of(entry, struct device, power.entry);
12} 12}
13 13
14extern void device_pm_add(struct device *); 14extern int device_pm_add(struct device *);
15extern void device_pm_remove(struct device *); 15extern void device_pm_remove(struct device *);
16extern int pm_sleep_lock(void);
17extern void pm_sleep_unlock(void);
18 16
19#else /* CONFIG_PM_SLEEP */ 17#else /* CONFIG_PM_SLEEP */
20 18
21 19static inline int device_pm_add(struct device *dev) { return 0; }
22static inline void device_pm_add(struct device *dev) 20static inline void device_pm_remove(struct device *dev) {}
23{
24}
25
26static inline void device_pm_remove(struct device *dev)
27{
28}
29
30static inline int pm_sleep_lock(void)
31{
32 return 0;
33}
34
35static inline void pm_sleep_unlock(void)
36{
37}
38 21
39#endif 22#endif
40 23