hp_accel: fix race in device removal

The work queue has to be flushed after the device has been made
inaccessible.  The patch closes a window during which a work queue might
remain active after the device is removed and would then lead to ACPI
calls with undefined behavior.

Signed-off-by: Oliver Neukum <[email protected]>
Acked-by: Eric Piel <[email protected]>
Acked-by: Pavel Machek <[email protected]>
Cc: Pavel Herrmann <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

drivers/hwmon/hp_accel.c

@@ -328,8 +328,8 @@ static int lis3lv02d_remove(struct acpi_device *device, int type)
 	lis3lv02d_joystick_disable();
 	lis3lv02d_poweroff(&lis3_dev);
 
-	flush_work(&hpled_led.work);
 	led_classdev_unregister(&hpled_led.led_classdev);
+	flush_work(&hpled_led.work);
 
 	return lis3lv02d_remove_fs(&lis3_dev);
 }