1 files changed, 32 insertions, 6 deletions

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 3b2d5df45e7a..00e667296360 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -67,23 +67,42 @@ static int __power_supply_changed_work(struct device *dev, void *data)
 
 static void power_supply_changed_work(struct work_struct *work)
 {
+	unsigned long flags;
 	struct power_supply *psy = container_of(work, struct power_supply,
 						changed_work);
 
 	dev_dbg(psy->dev, "%s\n", __func__);
 
-	class_for_each_device(power_supply_class, NULL, psy,
-			      __power_supply_changed_work);
-
-	power_supply_update_leds(psy);
-
-	kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
+	spin_lock_irqsave(&psy->changed_lock, flags);
+	if (psy->changed) {
+		psy->changed = false;
+		spin_unlock_irqrestore(&psy->changed_lock, flags);
+		class_for_each_device(power_supply_class, NULL, psy,
+				      __power_supply_changed_work);
+		power_supply_update_leds(psy);
+		kobject_uevent(&psy->dev->kobj, KOBJ_CHANGE);
+		spin_lock_irqsave(&psy->changed_lock, flags);
+	}
+	/*
+	 * Dependent power supplies (e.g. battery) may have changed state
+	 * as a result of this event, so poll again and hold the
+	 * wakeup_source until all events are processed.
+	 */
+	if (!psy->changed)
+		pm_relax(psy->dev);
+	spin_unlock_irqrestore(&psy->changed_lock, flags);
 }
 
 void power_supply_changed(struct power_supply *psy)
 {
+	unsigned long flags;
+
 	dev_dbg(psy->dev, "%s\n", __func__);
 
+	spin_lock_irqsave(&psy->changed_lock, flags);
+	psy->changed = true;
+	pm_stay_awake(psy->dev);
+	spin_unlock_irqrestore(&psy->changed_lock, flags);
 	schedule_work(&psy->changed_work);
 }
 EXPORT_SYMBOL_GPL(power_supply_changed);
@@ -500,6 +519,11 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 		goto check_supplies_failed;
 	}
 
+	spin_lock_init(&psy->changed_lock);
+	rc = device_init_wakeup(dev, true);
+	if (rc)
+		goto wakeup_init_failed;
+
 	rc = kobject_set_name(&dev->kobj, "%s", psy->name);
 	if (rc)
 		goto kobject_set_name_failed;
@@ -529,6 +553,7 @@ create_triggers_failed:
 register_cooler_failed:
 	psy_unregister_thermal(psy);
 register_thermal_failed:
+wakeup_init_failed:
 	device_del(dev);
 kobject_set_name_failed:
 device_add_failed:
@@ -546,6 +571,7 @@ void power_supply_unregister(struct power_supply *psy)
 	power_supply_remove_triggers(psy);
 	psy_unregister_cooler(psy);
 	psy_unregister_thermal(psy);
+	device_init_wakeup(psy->dev, false);
 	device_unregister(psy->dev);
 }
 EXPORT_SYMBOL_GPL(power_supply_unregister);