[PATCH] one less word in struct device

This saves a word from "struct device" ... there's a refcounting mechanism
stub that's rather ineffective (the values are never even tested!), which
can safely be deleted.  With this patch it uses normal device refcounting,
so any potential users of the pm_parent mechanism will be more correct.
(That mechanism is actually unusable for now though; it does nothing.)
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

 drivers/base/power/main.c |   26 +++-----------------------
 include/linux/pm.h        |    1 -
 2 files changed, 3 insertions(+), 24 deletions(-)

drivers/base/power/main.c

@@ -30,23 +30,6 @@ LIST_HEAD(dpm_off_irq);
 DECLARE_MUTEX(dpm_sem);
 DECLARE_MUTEX(dpm_list_sem);
 
-/*
- * PM Reference Counting.
- */
-
-static inline void device_pm_hold(struct device * dev)
-{
-	if (dev)
-		atomic_inc(&dev->power.pm_users);
-}
-
-static inline void device_pm_release(struct device * dev)
-{
-	if (dev)
-		atomic_dec(&dev->power.pm_users);
-}
-
-
 /**
  *	device_pm_set_parent - Specify power dependency.
  *	@dev:		Device who needs power.
@@ -62,10 +45,8 @@ static inline void device_pm_release(struct device * dev)
 
 void device_pm_set_parent(struct device * dev, struct device * parent)
 {
-	struct device * old_parent = dev->power.pm_parent;
-	device_pm_release(old_parent);
-	dev->power.pm_parent = parent;
-	device_pm_hold(parent);
+	put_device(dev->power.pm_parent);
+	dev->power.pm_parent = get_device(parent);
 }
 EXPORT_SYMBOL_GPL(device_pm_set_parent);
 
@@ -75,7 +56,6 @@ int device_pm_add(struct device * dev)
 
 	pr_debug("PM: Adding info for %s:%s\n",
 		 dev->bus ? dev->bus->name : "No Bus", dev->kobj.name);
-	atomic_set(&dev->power.pm_users, 0);
 	down(&dpm_list_sem);
 	list_add_tail(&dev->power.entry, &dpm_active);
 	device_pm_set_parent(dev, dev->parent);
@@ -91,7 +71,7 @@ void device_pm_remove(struct device * dev)
 		 dev->bus ? dev->bus->name : "No Bus", dev->kobj.name);
 	down(&dpm_list_sem);
 	dpm_sysfs_remove(dev);
-	device_pm_release(dev->power.pm_parent);
+	put_device(dev->power.pm_parent);
 	list_del_init(&dev->power.entry);
 	up(&dpm_list_sem);
 }

include/linux/pm.h

@@ -224,7 +224,6 @@ struct dev_pm_info {
 	unsigned		should_wakeup:1;
 	pm_message_t		prev_state;
 	void			* saved_state;
-	atomic_t		pm_users;
 	struct device		* pm_parent;
 	struct list_head	entry;
 #endif