Index: linux-2.6/drivers/base/power/main.c
===================================================================
--- linux-2.6.orig/drivers/base/power/main.c
+++ linux-2.6/drivers/base/power/main.c
@@ -433,21 +433,17 @@ static int device_resume_noirq(struct de
 		error = pm_noirq_op(dev, dev->bus->pm, state);
 		if (error)
 			goto End;
-	}
-
-	if (dev->type && dev->type->pm) {
+	} else if (dev->type && dev->type->pm) {
 		pm_dev_dbg(dev, state, "EARLY type ");
 		error = pm_noirq_op(dev, dev->type->pm, state);
 		if (error)
 			goto End;
-	}
-
-	if (dev->class && dev->class->pm) {
+	} else if (dev->class && dev->class->pm) {
 		pm_dev_dbg(dev, state, "EARLY class ");
 		error = pm_noirq_op(dev, dev->class->pm, state);
 	}
 
-End:
+ End:
 	TRACE_RESUME(error);
 	return error;
 }
@@ -532,21 +528,18 @@ static int device_resume(struct device *
 		if (dev->bus->pm) {
 			pm_dev_dbg(dev, state, "");
 			error = pm_op(dev, dev->bus->pm, state);
+			goto End;
 		} else if (dev->bus->resume) {
 			pm_dev_dbg(dev, state, "legacy ");
 			error = legacy_resume(dev, dev->bus->resume);
-		}
-		if (error)
 			goto End;
+		}
 	}
 
-	if (dev->type) {
-		if (dev->type->pm) {
-			pm_dev_dbg(dev, state, "type ");
-			error = pm_op(dev, dev->type->pm, state);
-		}
-		if (error)
-			goto End;
+	if (dev->type && dev->type->pm) {
+		pm_dev_dbg(dev, state, "type ");
+		error = pm_op(dev, dev->type->pm, state);
+		goto End;
 	}
 
 	if (dev->class) {
@@ -558,6 +551,7 @@ static int device_resume(struct device *
 			error = legacy_resume(dev, dev->class->resume);
 		}
 	}
+
  End:
 	device_unlock(dev);
 	complete_all(&dev->power.completion);
@@ -644,19 +638,18 @@ static void device_complete(struct devic
 		dev->pwr_domain->ops.complete(dev);
 	}
 
-	if (dev->class && dev->class->pm && dev->class->pm->complete) {
-		pm_dev_dbg(dev, state, "completing class ");
-		dev->class->pm->complete(dev);
-	}
-
-	if (dev->type && dev->type->pm && dev->type->pm->complete) {
-		pm_dev_dbg(dev, state, "completing type ");
-		dev->type->pm->complete(dev);
-	}
-
-	if (dev->bus && dev->bus->pm && dev->bus->pm->complete) {
+	if (dev->bus && dev->bus->pm) {
 		pm_dev_dbg(dev, state, "completing ");
-		dev->bus->pm->complete(dev);
+		if (dev->bus->pm->complete)
+			dev->bus->pm->complete(dev);
+	} else if (dev->type && dev->type->pm) {
+		pm_dev_dbg(dev, state, "completing type ");
+		if (dev->type->pm->complete)
+			dev->type->pm->complete(dev);
+	} else if (dev->class && dev->class->pm) {
+		pm_dev_dbg(dev, state, "completing class ");
+		if (dev->class->pm->complete)
+			dev->class->pm->complete(dev);
 	}
 
 	device_unlock(dev);
@@ -741,27 +734,23 @@ static pm_message_t resume_event(pm_mess
  */
 static int device_suspend_noirq(struct device *dev, pm_message_t state)
 {
-	int error = 0;
+	int error;
 
-	if (dev->class && dev->class->pm) {
-		pm_dev_dbg(dev, state, "LATE class ");
-		error = pm_noirq_op(dev, dev->class->pm, state);
+	if (dev->bus && dev->bus->pm) {
+		pm_dev_dbg(dev, state, "LATE ");
+		error = pm_noirq_op(dev, dev->bus->pm, state);
 		if (error)
-			goto End;
-	}
-
-	if (dev->type && dev->type->pm) {
+			return error;
+	} else if (dev->type && dev->type->pm) {
 		pm_dev_dbg(dev, state, "LATE type ");
 		error = pm_noirq_op(dev, dev->type->pm, state);
 		if (error)
-			goto End;
-	}
-
-	if (dev->bus && dev->bus->pm) {
-		pm_dev_dbg(dev, state, "LATE ");
-		error = pm_noirq_op(dev, dev->bus->pm, state);
+			return error;
+	} else if (dev->class && dev->class->pm) {
+		pm_dev_dbg(dev, state, "LATE class ");
+		error = pm_noirq_op(dev, dev->class->pm, state);
 		if (error)
-			goto End;
+			return error;
 	}
 
 	if (dev->pwr_domain) {
@@ -769,8 +758,7 @@ static int device_suspend_noirq(struct d
 		pm_noirq_op(dev, &dev->pwr_domain->ops, state);
 	}
 
-End:
-	return error;
+	return 0;
 }
 
 /**
@@ -857,40 +845,36 @@ static int __device_suspend(struct devic
 		goto End;
 	}
 
-	if (dev->class) {
-		if (dev->class->pm) {
-			pm_dev_dbg(dev, state, "class ");
-			error = pm_op(dev, dev->class->pm, state);
-		} else if (dev->class->suspend) {
-			pm_dev_dbg(dev, state, "legacy class ");
-			error = legacy_suspend(dev, state, dev->class->suspend);
-		}
-		if (error)
-			goto End;
-	}
-
-	if (dev->type) {
-		if (dev->type->pm) {
-			pm_dev_dbg(dev, state, "type ");
-			error = pm_op(dev, dev->type->pm, state);
-		}
-		if (error)
-			goto End;
-	}
-
 	if (dev->bus) {
 		if (dev->bus->pm) {
 			pm_dev_dbg(dev, state, "");
 			error = pm_op(dev, dev->bus->pm, state);
+			goto Domain;
 		} else if (dev->bus->suspend) {
 			pm_dev_dbg(dev, state, "legacy ");
 			error = legacy_suspend(dev, state, dev->bus->suspend);
+			goto Domain;
 		}
-		if (error)
-			goto End;
 	}
 
-	if (dev->pwr_domain) {
+	if (dev->type && dev->type->pm) {
+		pm_dev_dbg(dev, state, "type ");
+		error = pm_op(dev, dev->type->pm, state);
+		goto Domain;
+	}
+
+	if (dev->class) {
+		if (dev->class->pm) {
+			pm_dev_dbg(dev, state, "class ");
+			error = pm_op(dev, dev->class->pm, state);
+		} else if (dev->class->suspend) {
+			pm_dev_dbg(dev, state, "legacy class ");
+			error = legacy_suspend(dev, state, dev->class->suspend);
+		}
+	}
+
+ Domain:
+	if (!error && dev->pwr_domain) {
 		pm_dev_dbg(dev, state, "power domain ");
 		pm_op(dev, &dev->pwr_domain->ops, state);
 	}
@@ -985,25 +969,24 @@ static int device_prepare(struct device
 
 	device_lock(dev);
 
-	if (dev->bus && dev->bus->pm && dev->bus->pm->prepare) {
+	if (dev->bus && dev->bus->pm) {
 		pm_dev_dbg(dev, state, "preparing ");
-		error = dev->bus->pm->prepare(dev);
+		if (dev->bus->pm->prepare)
+			error = dev->bus->pm->prepare(dev);
 		suspend_report_result(dev->bus->pm->prepare, error);
 		if (error)
 			goto End;
-	}
-
-	if (dev->type && dev->type->pm && dev->type->pm->prepare) {
+	} else if (dev->type && dev->type->pm) {
 		pm_dev_dbg(dev, state, "preparing type ");
-		error = dev->type->pm->prepare(dev);
+		if (dev->type->pm->prepare)
+			error = dev->type->pm->prepare(dev);
 		suspend_report_result(dev->type->pm->prepare, error);
 		if (error)
 			goto End;
-	}
-
-	if (dev->class && dev->class->pm && dev->class->pm->prepare) {
+	} else if (dev->class && dev->class->pm) {
 		pm_dev_dbg(dev, state, "preparing class ");
-		error = dev->class->pm->prepare(dev);
+		if (dev->class->pm->prepare)
+			error = dev->class->pm->prepare(dev);
 		suspend_report_result(dev->class->pm->prepare, error);
 		if (error)
 			goto End;
Index: linux-2.6/drivers/base/power/runtime.c
===================================================================
--- linux-2.6.orig/drivers/base/power/runtime.c
+++ linux-2.6/drivers/base/power/runtime.c
@@ -214,9 +214,9 @@ static int rpm_idle(struct device *dev,
 
 	dev->power.idle_notification = true;
 
-	if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle)
+	if (dev->bus && dev->bus->pm)
 		callback = dev->bus->pm->runtime_idle;
-	else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle)
+	else if (dev->type && dev->type->pm)
 		callback = dev->type->pm->runtime_idle;
 	else if (dev->class && dev->class->pm)
 		callback = dev->class->pm->runtime_idle;
@@ -382,9 +382,9 @@ static int rpm_suspend(struct device *de
 
 	__update_runtime_status(dev, RPM_SUSPENDING);
 
-	if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
+	if (dev->bus && dev->bus->pm)
 		callback = dev->bus->pm->runtime_suspend;
-	else if (dev->type && dev->type->pm && dev->type->pm->runtime_suspend)
+	else if (dev->type && dev->type->pm)
 		callback = dev->type->pm->runtime_suspend;
 	else if (dev->class && dev->class->pm)
 		callback = dev->class->pm->runtime_suspend;
@@ -584,9 +584,9 @@ static int rpm_resume(struct device *dev
 	if (dev->pwr_domain)
 		rpm_callback(dev->pwr_domain->ops.runtime_resume, dev);
 
-	if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
+	if (dev->bus && dev->bus->pm)
 		callback = dev->bus->pm->runtime_resume;
-	else if (dev->type && dev->type->pm && dev->type->pm->runtime_resume)
+	else if (dev->type && dev->type->pm)
 		callback = dev->type->pm->runtime_resume;
 	else if (dev->class && dev->class->pm)
 		callback = dev->class->pm->runtime_resume;
Index: linux-2.6/Documentation/power/devices.txt
===================================================================
--- linux-2.6.orig/Documentation/power/devices.txt
+++ linux-2.6/Documentation/power/devices.txt
@@ -249,23 +249,17 @@ various phases always run after tasks ha
 unfrozen.  Furthermore, the *_noirq phases run at a time when IRQ handlers have
 been disabled (except for those marked with the IRQ_WAKEUP flag).
 
-Most phases use bus, type, and class callbacks (that is, methods defined in
-dev->bus->pm, dev->type->pm, and dev->class->pm).  The prepare and complete
-phases are exceptions; they use only bus callbacks.  When multiple callbacks
-are used in a phase, they are invoked in the order: <class, type, bus> during
-power-down transitions and in the opposite order during power-up transitions.
-For example, during the suspend phase the PM core invokes
-
-	dev->class->pm.suspend(dev);
-	dev->type->pm.suspend(dev);
-	dev->bus->pm.suspend(dev);
-
-before moving on to the next device, whereas during the resume phase the core
-invokes
-
-	dev->bus->pm.resume(dev);
-	dev->type->pm.resume(dev);
-	dev->class->pm.resume(dev);
+All phases use bus, type, or class callbacks (that is, methods defined in
+dev->bus->pm, dev->type->pm, or dev->class->pm).  These callbacks are mutually
+exclusive, so if the bus provides a struct dev_pm_ops object pointed to by its
+pm field (i.e. both dev->bus and dev->bus->pm are defined), the callbacks
+included in that object (i.e. dev->bus->pm) will be used.  In turn, if the
+device type provides a struct dev_pm_ops object pointed to by its pm field
+(i.e. both dev->type and dev->type->pm are defined), the PM core will used the
+callbacks from that object (i.e. dev->type->pm).  Finally, if the pm fields of
+both the bus and device type objects are NULL (or those objects do not exist),
+the callbacks provided by the class (that is, the callbacks from dev->class->pm)
+will be used.
 
 These callbacks may in turn invoke device- or driver-specific methods stored in
 dev->driver->pm, but they don't have to.
