Merge tag 'pm-4.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "Fix a regression from the 4.15 cycle that caused the system suspend
  and resume overhead to increase on many systems and triggered more
  serious problems on some of them (Rafael Wysocki)"

* tag 'pm-4.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / core: Fix direct_complete handling for devices with no callbacks

Author: torvalds

drivers/base/power/main.c

@@ -1923,10 +1923,8 @@ static int device_prepare(struct device *dev, pm_message_t state)
 
 	dev->power.wakeup_path = false;
 
-	if (dev->power.no_pm_callbacks) {
-		ret = 1;	/* Let device go direct_complete */
+	if (dev->power.no_pm_callbacks)
 		goto unlock;
-	}
 
 	if (dev->pm_domain)
 		callback = dev->pm_domain->ops.prepare;
@@ -1960,7 +1958,8 @@ static int device_prepare(struct device *dev, pm_message_t state)
 	 */
 	spin_lock_irq(&dev->power.lock);
 	dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
-		pm_runtime_suspended(dev) && ret > 0 &&
+		((pm_runtime_suspended(dev) && ret > 0) ||
+		 dev->power.no_pm_callbacks) &&
 		!dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP);
 	spin_unlock_irq(&dev->power.lock);
 	return 0;