[power] Get rid of internal spinlock.

We don't need the spinlock to protect the lists (at least not now), since 
we have a semaphore to synchronize all operations device PM operations.

drivers/base/power/main.c

@@ -29,7 +29,6 @@ LIST_HEAD(dpm_suspended);
 LIST_HEAD(dpm_off);
 LIST_HEAD(dpm_off_irq);
 
-spinlock_t dpm_lock = SPIN_LOCK_UNLOCKED;
 DECLARE_MUTEX(dpm_sem);
 
 static struct attribute power_attrs[] = {
@@ -47,9 +46,7 @@ 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);
 	down(&dpm_sem);
-	spin_lock(&dpm_lock);
 	list_add_tail(&dev->power.entry,&dpm_active);
-	spin_unlock(&dpm_lock);
 	error = sysfs_create_group(&dev->kobj,&pm_attr_group);
 	up(&dpm_sem);
 	return error;
@@ -61,8 +58,6 @@ void device_pm_remove(struct device * dev)
 		 dev->bus ? dev->bus->name : "No Bus", dev->kobj.name);
 	down(&dpm_sem);
 	sysfs_remove_group(&dev->kobj,&pm_attr_group);
-	spin_lock(&dpm_lock);
 	list_del(&dev->power.entry);
-	spin_unlock(&dpm_lock);
 	up(&dpm_sem);
 }

drivers/base/power/power.h

@@ -4,11 +4,6 @@
  */
 extern struct semaphore dpm_sem;
 
-/*
- * Used to protect PM lists.
- */
-extern spinlock_t dpm_lock;
-
 /* 
  * The PM lists.
  */

drivers/base/power/resume.c

@@ -39,17 +39,13 @@ static int resume_device(struct device * dev)
 
 int dpm_resume(void)
 {
-	spin_lock(&dpm_lock);
 	while(!list_empty(&dpm_suspended)) {
 		struct list_head * entry = dpm_suspended.next;
 		struct device * dev = to_device(entry);
 		list_del_init(entry);
-		spin_unlock(&dpm_lock);
 		resume_device(dev);
-		spin_lock(&dpm_lock);
 		list_add_tail(entry,&dpm_active);
 	}
-	spin_unlock(&dpm_lock);
 	return 0;
 }
 
@@ -95,14 +91,12 @@ static void power_up_device(struct device * dev)
 
 void dpm_power_up_irq(void)
 {
-	spin_lock_irq(&dpm_lock);
 	while(!list_empty(&dpm_off_irq)) {
 		struct list_head * entry = dpm_off_irq.next;
 		list_del_init(entry);
 		power_up_device(to_device(entry));
 		list_add_tail(entry,&dpm_suspended);
 	}
-	spin_unlock_irq(&dpm_lock);
 }
 
 
@@ -116,14 +110,12 @@ void dpm_power_up_irq(void)
 
 void dpm_power_up(void)
 {
-	spin_lock(&dpm_lock);
 	while (!list_empty(&dpm_off)) {
 		struct list_head * entry = dpm_off.next;
 		list_del_init(entry);
 		power_up_device(to_device(entry));
 		list_add_tail(entry,&dpm_suspended);
 	}
-	spin_unlock(&dpm_lock);
 }
 
 

drivers/base/power/suspend.c

@@ -71,15 +71,12 @@ int device_pm_suspend(u32 state)
 	int error = 0;
 
 	down(&dpm_sem);
-	spin_lock(&dpm_lock);
 	while(!list_empty(&dpm_active)) {
 		struct list_head * entry = dpm_active.prev;
 		struct device * dev = to_device(entry);
 		list_del_init(entry);
-		spin_unlock(&dpm_lock);
 		error = suspend_device(dev,state);
 
-		spin_lock(&dpm_lock);
 		if (!error)
 			list_add(entry,&dpm_suspended);
 		else {
@@ -87,7 +84,6 @@ int device_pm_suspend(u32 state)
 			goto Error;
 		}
 	}
-	spin_unlock(&dpm_lock);
 
 	if ((error = sysdev_save(state)))
 		goto Error;
@@ -129,15 +125,12 @@ static int power_down_device(struct device * dev, u32 state)
 
 static int dpm_power_down(u32 state)
 {
-	spin_lock(&dpm_lock);
 	while(!list_empty(&dpm_suspended)) {
 		struct list_head * entry = dpm_suspended.prev;
 		int error;
 
 		list_del_init(entry);
-		spin_unlock(&dpm_lock);
 		error = power_down_device(to_device(entry),state);
-		spin_lock(&dpm_lock);
 		if (!error)
 			list_add(entry,&dpm_off);
 		else if (error == -EAGAIN)
@@ -147,7 +140,6 @@ static int dpm_power_down(u32 state)
 			return error;
 		}
 	}
-	spin_unlock(&dpm_lock);
 	return 0;
 }
 
@@ -166,12 +158,10 @@ static int dpm_power_down_irq(u32 state)
 	struct device * dev;
 	int error = 0;
 
-	spin_lock_irq(&dpm_lock);
 	list_for_each_entry_reverse(dev,&dpm_off_irq,power.entry) {
 		if ((error = power_down_device(dev,state)))
 			break;
 	}
-	spin_unlock_irq(&dpm_lock);
 	return error;
 }