ACPI: Battery: remove cycle from battery removal.

get_property() should not call battery_update(), it also should call
get_status() only if battery is present to avoid cycle and oops.

Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Tested-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Acked-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/acpi/battery.c

@@ -132,18 +132,19 @@ static int acpi_battery_technology(struct acpi_battery *battery)
 	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
 }
 
-static int acpi_battery_update(struct acpi_battery *battery);
+static int acpi_battery_get_state(struct acpi_battery *battery);
 
 static int acpi_battery_get_property(struct power_supply *psy,
 				     enum power_supply_property psp,
 				     union power_supply_propval *val)
 {
 	struct acpi_battery *battery = to_acpi_battery(psy);
 
-	if ((!acpi_battery_present(battery)) &&
-	     psp != POWER_SUPPLY_PROP_PRESENT)
+	if (acpi_battery_present(battery)) {
+		/* run battery update only if it is present */
+		acpi_battery_get_state(battery);
+	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
 		return -ENODEV;
-	acpi_battery_update(battery);
 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		if (battery->state & 0x01)
@@ -457,6 +458,7 @@ static void sysfs_remove_battery(struct acpi_battery *battery)
 		return;
 	device_remove_file(battery->bat.dev, &alarm_attr);
 	power_supply_unregister(&battery->bat);
+	battery->bat.dev = NULL;
 }
 
 static int acpi_battery_update(struct acpi_battery *battery)