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PM: Handle device registrations during suspend/resume

Sfoglia il codice sorgente 
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>
This commit is contained in:
Rafael J. Wysocki
2008-03-12 00:57:22 +01:00
committato da Greg Kroah-Hartman
parent 6bcf19d02a
commit 58aca23226
5 ha cambiato i file con 40 aggiunte e 52 eliminazioni
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23
drivers/base/power/power.h
Vedi File

@@ -11,30 +11,13 @@ static inline struct device *to_device(struct list_head *entry)
return container_of(entry, struct device, power.entry);
}
extern void device_pm_add(struct device *);
extern int device_pm_add(struct device *);
extern void device_pm_remove(struct device *);
extern int pm_sleep_lock(void);
extern void pm_sleep_unlock(void);
#else /* CONFIG_PM_SLEEP */
static inline void device_pm_add(struct device *dev)
{
}
static inline void device_pm_remove(struct device *dev)
{
}
static inline int pm_sleep_lock(void)
{
return 0;
}
static inline void pm_sleep_unlock(void)
{
}
static inline int device_pm_add(struct device *dev) { return 0; }
static inline void device_pm_remove(struct device *dev) {}
#endif