Whom based his on the Keyspan driver by Hugh Blemings <hugh@blemings.org>
 */
 
-#define DRIVER_VERSION "v.1.3.2"
+#define DRIVER_VERSION "v.1.3.3"
 #define DRIVER_AUTHOR "Kevin Lloyd <klloyd@sierrawireless.com>"
 #define DRIVER_DESC "USB Driver for Sierra Wireless USB modems"
 
                        val |= 0x02;
 
                /* If composite device then properly report interface */
-               if (serial->num_ports == 1)
+               if (serial->num_ports == 1) {
                        interface = sierra_calc_interface(serial);
 
+                       /* Control message is sent only to interfaces with
+                        * interrupt_in endpoints
+                        */
+                       if (port->interrupt_in_urb) {
+                               /* send control message */
+                               return usb_control_msg(serial->dev,
+                                       usb_rcvctrlpipe(serial->dev, 0),
+                                       0x22, 0x21, val, interface,
+                                       NULL, 0, USB_CTRL_SET_TIMEOUT);
+                       }
+               }
+
                /* Otherwise the need to do non-composite mapping */
                else {
                        if (port->bulk_out_endpointAddress == 2)
                                interface = 1;
                        else if (port->bulk_out_endpointAddress == 5)
                                interface = 2;
-               }
 
-               return usb_control_msg(serial->dev,
+                       return usb_control_msg(serial->dev,
                                usb_rcvctrlpipe(serial->dev, 0),
                                0x22, 0x21, val, interface,
                                NULL, 0, USB_CTRL_SET_TIMEOUT);
+
+               }
        }
 
        return 0;