Index: sys/dev/usb/serial/ugensa.c
===================================================================
--- sys/dev/usb/serial/ugensa.c
+++ sys/dev/usb/serial/ugensa.c
@@ -162,6 +162,8 @@
 	{USB_VPI(USB_VENDOR_KYOCERA2, USB_PRODUCT_KYOCERA2_CDMA_MSM_K, 1)},
 	{USB_VPI(USB_VENDOR_HP, USB_PRODUCT_HP_49GPLUS, 1)},
 	{USB_VPI(USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_FLEXPACKGPS, 3)},
+	{USB_VENDOR(USB_VENDOR_GOOGLE), USB_IFACE_CLASS(UICLASS_VENDOR),
+		USB_IFACE_SUBCLASS(0x50), USB_IFACE_PROTOCOL(0x01), USB_DRIVER_INFO(10)},
 };
 
 DRIVER_MODULE(ugensa, uhub, ugensa_driver, ugensa_devclass, NULL, 0);
@@ -211,6 +213,11 @@
 			/* Not a serial port, most likely a SD reader */
 			continue;
 
+		/* XXX: default is 0, right? */
+		if (uaa->info.bInterfaceSubClass != 0 && iface->idesc->bInterfaceSubClass != uaa->info.bInterfaceSubClass)
+			/* Not a serial port, most likely an I2C or flash interface */
+			continue;
+
 		/* Loop over all endpoints pairwise */
 		for (x = 0; x < maxports && sc->sc_nports < UGENSA_PORT_MAX; x++) {
 
@@ -234,11 +241,12 @@
 				break;
 			}
 
+			/* XXX: do any devices need it? leave it on for non-google? */
 			/* clear stall at first run */
-			mtx_lock(&sc->sc_mtx);
-			usbd_xfer_set_stall(ssc->sc_xfer[UGENSA_BULK_DT_WR]);
-			usbd_xfer_set_stall(ssc->sc_xfer[UGENSA_BULK_DT_RD]);
-			mtx_unlock(&sc->sc_mtx);
+			/* mtx_lock(&sc->sc_mtx); */
+			/* usbd_xfer_set_stall(ssc->sc_xfer[UGENSA_BULK_DT_WR]); */
+			/* usbd_xfer_set_stall(ssc->sc_xfer[UGENSA_BULK_DT_RD]); */
+			/* mtx_unlock(&sc->sc_mtx); */
 
 			/* initialize port number */
 			ssc->sc_ucom_ptr->sc_portno = sc->sc_nports;