Index: if_urtwn.c
===================================================================
RCS file: /cvsroot/src/sys/dev/usb/if_urtwn.c,v
retrieving revision 1.57
diff -u -r1.57 if_urtwn.c
--- if_urtwn.c  8 Feb 2018 09:05:20 -0000       1.57
+++ if_urtwn.c  30 Apr 2018 05:19:31 -0000
@@ -483,7 +483,7 @@
       IFQ_SET_READY(&ifp->if_snd);
       memcpy(ifp->if_xname, device_xname(sc->sc_dev), IFNAMSIZ);

-       if_attach(ifp);
+       if_initialize(ifp);
       ieee80211_ifattach(ic);

       /* override default methods */
@@ -508,6 +508,9 @@
       sc->sc_txtap.wt_ihdr.it_len = htole16(sc->sc_txtap_len);
       sc->sc_txtap.wt_ihdr.it_present = htole32(URTWN_TX_RADIOTAP_PRESENT);

+       ifp->if_percpuq = if_percpuq_create(ifp);
+       if_register(ifp);
+
       ieee80211_announce(ic);

       usbd_add_drv_event(USB_EVENT_DRIVER_ATTACH, sc->sc_udev, sc->sc_dev);