The LED luminance level is normally lower when no button is pressed.
Reviewed-by: NEduard Hasenleithner <eduard@hasenleithner.at>
Tested-by: NEduard Hasenleithner <eduard@hasenleithner.at>
Signed-off-by: NPing Cheng <pingc@wacom.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>