usbduxsub_tmp->urbIn = NULL;
        }
        if (usbduxsub_tmp->urbOut) {
-               if (usbduxsub_tmp->ao_cmd_running) {
-                       usbduxsub_tmp->ao_cmd_running = 0;
-                       usbduxsub_unlink_OutURBs(usbduxsub_tmp);
-               }
+               /* force unlink all urbs */
+               usbdux_ao_stop(usbduxsub_tmp, 1);
                for (i = 0; i < usbduxsub_tmp->numOfOutBuffers; i++) {
                        if (usbduxsub_tmp->urbOut[i]->transfer_buffer) {
                                kfree(usbduxsub_tmp->
                                    NULL;
                        }
                        if (usbduxsub_tmp->urbOut[i]) {
-                               usb_kill_urb(usbduxsub_tmp->urbOut[i]);
                                usb_free_urb(usbduxsub_tmp->urbOut[i]);
                                usbduxsub_tmp->urbOut[i] = NULL;
                        }
        usbduxsub_tmp->dac_commands = NULL;
        kfree(usbduxsub_tmp->dux_commands);
        usbduxsub_tmp->dux_commands = NULL;
-       usbduxsub_tmp->ao_cmd_running = 0;
        usbduxsub_tmp->pwm_cmd_running = 0;
 }