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 <oneukum@suse.de>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Pavel Herrmann <morpheus.ibis@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/hwmon/hp_accel.c b/drivers/hwmon/hp_accel.c
index c8ab5051667217ab02321ec8a2a2d14db5a48104..7580f55e67e3cf1560437b428d9fb1e5b8e411d0 100644 (file)
--- a/drivers/hwmon/hp_accel.c
+++ b/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);
 }