diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 6e7b2a12860d..e48fc98e71c4 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -56,6 +56,10 @@
 /* Battery power unit: 0 means mW, 1 means mA */
 #define ACPI_BATTERY_POWER_UNIT_MA	1
 
+#define ACPI_BATTERY_STATE_DISCHARGING	0x1
+#define ACPI_BATTERY_STATE_CHARGING	0x2
+#define ACPI_BATTERY_STATE_CRITICAL	0x4
+
 #define _COMPONENT		ACPI_BATTERY_COMPONENT
 
 ACPI_MODULE_NAME("battery");
@@ -169,7 +173,7 @@ static int acpi_battery_get_state(struct acpi_battery *battery);
 
 static int acpi_battery_is_charged(struct acpi_battery *battery)
 {
-	/* either charging or discharging */
+	/* charging, discharging or critical low */
 	if (battery->state != 0)
 		return 0;
 
@@ -204,9 +208,9 @@ static int acpi_battery_get_property(struct power_supply *psy,
 		return -ENODEV;
 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
-		if (battery->state & 0x01)
+		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
 			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
-		else if (battery->state & 0x02)
+		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
 			val->intval = POWER_SUPPLY_STATUS_CHARGING;
 		else if (acpi_battery_is_charged(battery))
 			val->intval = POWER_SUPPLY_STATUS_FULL;
@@ -269,6 +273,17 @@ static int acpi_battery_get_property(struct power_supply *psy,
 		else
 			val->intval = 0;
 		break;
+	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
+		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
+		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
+			(battery->capacity_now <= battery->alarm))
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
+		else if (acpi_battery_is_charged(battery))
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
+		else
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
+		break;
 	case POWER_SUPPLY_PROP_MODEL_NAME:
 		val->strval = battery->model_number;
 		break;
@@ -296,6 +311,7 @@ static enum power_supply_property charge_battery_props[] = {
 	POWER_SUPPLY_PROP_CHARGE_FULL,
 	POWER_SUPPLY_PROP_CHARGE_NOW,
 	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
@@ -313,6 +329,7 @@ static enum power_supply_property energy_battery_props[] = {
 	POWER_SUPPLY_PROP_ENERGY_FULL,
 	POWER_SUPPLY_PROP_ENERGY_NOW,
 	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
@@ -605,7 +622,8 @@ static int sysfs_add_battery(struct acpi_battery *battery)
 	battery->bat.type = POWER_SUPPLY_TYPE_BATTERY;
 	battery->bat.get_property = acpi_battery_get_property;
 
-	result = power_supply_register(&battery->device->dev, &battery->bat);
+	result = power_supply_register_no_ws(&battery->device->dev, &battery->bat);
+
 	if (result)
 		return result;
 	return device_create_file(battery->bat.dev, &alarm_attr);
@@ -696,7 +714,7 @@ static void acpi_battery_quirks(struct acpi_battery *battery)
 	}
 }
 
-static int acpi_battery_update(struct acpi_battery *battery)
+static int acpi_battery_update(struct acpi_battery *battery, bool resume)
 {
 	int result, old_present = acpi_battery_present(battery);
 	result = acpi_battery_get_status(battery);
@@ -707,6 +725,10 @@ static int acpi_battery_update(struct acpi_battery *battery)
 		battery->update_time = 0;
 		return 0;
 	}
+
+	if (resume)
+		return 0;
+
 	if (!battery->update_time ||
 	    old_present != acpi_battery_present(battery)) {
 		result = acpi_battery_get_info(battery);
@@ -720,7 +742,19 @@ static int acpi_battery_update(struct acpi_battery *battery)
 			return result;
 	}
 	result = acpi_battery_get_state(battery);
+	if (result)
+		return result;
 	acpi_battery_quirks(battery);
+
+	/*
+	 * Wakeup the system if battery is critical low
+	 * or lower than the alarm level
+	 */
+	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
+	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
+            (battery->capacity_now <= battery->alarm)))
+		pm_wakeup_event(&battery->device->dev, 0);
+
 	return result;
 }
 
@@ -915,7 +949,7 @@ static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
 static int acpi_battery_read(int fid, struct seq_file *seq)
 {
 	struct acpi_battery *battery = seq->private;
-	int result = acpi_battery_update(battery);
+	int result = acpi_battery_update(battery, false);
 	return acpi_print_funcs[fid](seq, result);
 }
 
@@ -1030,7 +1064,7 @@ static void acpi_battery_notify(struct acpi_device *device, u32 event)
 	old = battery->bat.dev;
 	if (event == ACPI_BATTERY_NOTIFY_INFO)
 		acpi_battery_refresh(battery);
-	acpi_battery_update(battery);
+	acpi_battery_update(battery, false);
 	acpi_bus_generate_netlink_event(device->pnp.device_class,
 					dev_name(&device->dev), event,
 					acpi_battery_present(battery));
@@ -1045,13 +1079,27 @@ static int battery_notify(struct notifier_block *nb,
 {
 	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
 						    pm_nb);
+	int result;
+
 	switch (mode) {
 	case PM_POST_HIBERNATION:
 	case PM_POST_SUSPEND:
-		if (battery->bat.dev) {
-			sysfs_remove_battery(battery);
-			sysfs_add_battery(battery);
-		}
+		if (!acpi_battery_present(battery))
+			return 0;
+
+		if (!battery->bat.dev) {
+			result = acpi_battery_get_info(battery);
+			if (result)
+				return result;
+
+			result = sysfs_add_battery(battery);
+			if (result)
+				return result;
+		} else
+			acpi_battery_refresh(battery);
+
+		acpi_battery_init_alarm(battery);
+		acpi_battery_get_state(battery);
 		break;
 	}
 
@@ -1087,7 +1135,7 @@ static int acpi_battery_add(struct acpi_device *device)
 	mutex_init(&battery->sysfs_lock);
 	if (acpi_has_method(battery->device->handle, "_BIX"))
 		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
-	result = acpi_battery_update(battery);
+	result = acpi_battery_update(battery, false);
 	if (result)
 		goto fail;
 #ifdef CONFIG_ACPI_PROCFS_POWER
@@ -1107,6 +1155,8 @@ static int acpi_battery_add(struct acpi_device *device)
 	battery->pm_nb.notifier_call = battery_notify;
 	register_pm_notifier(&battery->pm_nb);
 
+	device_init_wakeup(&device->dev, 1);
+
 	return result;
 
 fail:
@@ -1123,6 +1173,7 @@ static int acpi_battery_remove(struct acpi_device *device)
 
 	if (!device || !acpi_driver_data(device))
 		return -EINVAL;
+	device_init_wakeup(&device->dev, 0);
 	battery = acpi_driver_data(device);
 	unregister_pm_notifier(&battery->pm_nb);
 #ifdef CONFIG_ACPI_PROCFS_POWER
@@ -1149,7 +1200,7 @@ static int acpi_battery_resume(struct device *dev)
 		return -EINVAL;
 
 	battery->update_time = 0;
-	acpi_battery_update(battery);
+	acpi_battery_update(battery, true);
 	return 0;
 }
 #else
diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index 26606641fe44..5a5a24e7d43c 100644
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -537,7 +537,7 @@ static void psy_unregister_cooler(struct power_supply *psy)
 }
 #endif
 
-int power_supply_register(struct device *parent, struct power_supply *psy)
+int __power_supply_register(struct device *parent, struct power_supply *psy, bool ws)
 {
 	struct device *dev;
 	int rc;
@@ -568,7 +568,7 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 	}
 
 	spin_lock_init(&psy->changed_lock);
-	rc = device_init_wakeup(dev, true);
+	rc = device_init_wakeup(dev, ws);
 	if (rc)
 		goto wakeup_init_failed;
 
@@ -606,8 +606,19 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
 success:
 	return rc;
 }
+
+int power_supply_register(struct device *parent, struct power_supply *psy)
+{
+	return __power_supply_register(parent, psy, true);
+}
 EXPORT_SYMBOL_GPL(power_supply_register);
 
+int power_supply_register_no_ws(struct device *parent, struct power_supply *psy)
+{
+	return __power_supply_register(parent, psy, false);
+}
+EXPORT_SYMBOL_GPL(power_supply_register_no_ws);
+
 void power_supply_unregister(struct power_supply *psy)
 {
 	cancel_work_sync(&psy->changed_work);
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index c9dc4e09854c..f2b76aeaf4e4 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -264,6 +264,8 @@ static inline int power_supply_is_system_supplied(void) { return -ENOSYS; }
 
 extern int power_supply_register(struct device *parent,
 				 struct power_supply *psy);
+extern int power_supply_register_no_ws(struct device *parent,
+				 struct power_supply *psy);
 extern void power_supply_unregister(struct power_supply *psy);
 extern int power_supply_powers(struct power_supply *psy, struct device *dev);