/* default to enabling interface */
        altsetting = 0;
-       switch (ifnum) {
-               /* Composite mode; don't bind to the QMI/net interface as that
-                * gets handled by other drivers.
-                */
 
+       /* Composite mode; don't bind to the QMI/net interface as that
+        * gets handled by other drivers.
+        */
+
+       if (is_gobi1k) {
                /* Gobi 1K USB layout:
                 * 0: serial port (doesn't respond)
                 * 1: serial port (doesn't respond)
                 * 2: AT-capable modem port
                 * 3: QMI/net
-                *
-                * Gobi 2K+ USB layout:
+                */
+               if (ifnum == 2)
+                       dev_dbg(dev, "Modem port found\n");
+               else
+                       altsetting = -1;
+       } else {
+               /* Gobi 2K+ USB layout:
                 * 0: QMI/net
                 * 1: DM/DIAG (use libqcdm from ModemManager for communication)
                 * 2: AT-capable modem port
                 * 3: NMEA
                 */
-
-       case 1:
-               if (is_gobi1k)
+               switch (ifnum) {
+               case 0:
+                       /* Don't claim the QMI/net interface */
                        altsetting = -1;
-               else
+                       break;
+               case 1:
                        dev_dbg(dev, "Gobi 2K+ DM/DIAG interface found\n");
-               break;
-       case 2:
-               dev_dbg(dev, "Modem port found\n");
-               break;
-       case 3:
-               if (is_gobi1k)
-                       altsetting = -1;
-               else
+                       break;
+               case 2:
+                       dev_dbg(dev, "Modem port found\n");
+                       break;
+               case 3:
                        /*
                         * NMEA (serial line 9600 8N1)
                         * # echo "\$GPS_START" > /dev/ttyUSBx
                         * # echo "\$GPS_STOP"  > /dev/ttyUSBx
                         */
                        dev_dbg(dev, "Gobi 2K+ NMEA GPS interface found\n");
+                       break;
+               }
        }
 
 done: