58aca23226
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>
45 lines
775 B
C
45 lines
775 B
C
#ifdef CONFIG_PM_SLEEP
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/*
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* main.c
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*/
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extern struct list_head dpm_active; /* The active device list */
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static inline struct device *to_device(struct list_head *entry)
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{
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return container_of(entry, struct device, power.entry);
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}
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extern int device_pm_add(struct device *);
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extern void device_pm_remove(struct device *);
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#else /* CONFIG_PM_SLEEP */
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static inline int device_pm_add(struct device *dev) { return 0; }
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static inline void device_pm_remove(struct device *dev) {}
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#endif
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#ifdef CONFIG_PM
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/*
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* sysfs.c
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*/
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extern int dpm_sysfs_add(struct device *);
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extern void dpm_sysfs_remove(struct device *);
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#else /* CONFIG_PM */
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static inline int dpm_sysfs_add(struct device *dev)
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{
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return 0;
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}
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static inline void dpm_sysfs_remove(struct device *dev)
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{
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}
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#endif
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