Index: sys/dev/usb/umcs.c
===================================================================
RCS file: /cvsroot/src/sys/dev/usb/umcs.c,v
retrieving revision 1.6
diff -p -u -r1.6 umcs.c
--- sys/dev/usb/umcs.c	23 Mar 2014 20:20:38 -0000	1.6
+++ sys/dev/usb/umcs.c	4 May 2014 01:37:35 -0000
@@ -183,6 +183,19 @@ umcs7840_reg_dcr0(int phyport)
 }
 
 static int
+umcs7840_port2phy(struct umcs7840_softc *sc, int port)
+{
+
+	/*
+	 * On four port cards, endpoints are 0/1 for first,
+	 * 2/3 for second, ...
+	 * On two port cards, they are 0/1 for first, 4/5 for second.
+	 * On single port, just 0/1 will be used.
+	 */
+	return port * (sc->sc_numports == 2 ? 2 : 1);
+}
+
+static int
 umcs7840_match(device_t dev, cfdata_t match, void *aux)
 {
 	struct usb_attach_arg *uaa = aux;
@@ -309,21 +322,15 @@ umcs7840_attach(device_t parent, device_
 	uca.arg = sc;
 
 	for (i = 0; i < sc->sc_numports; i++) {
-		uca.bulkin = uca.bulkout = -1;
+		int phyport = umcs7840_port2phy(sc, i);
 
-		/*
-		 * On four port cards, endpoints are 0/1 for first,
-		 * 2/3 for second, ...
-		 * On two port cards, they are 0/1 for first, 4/5 for second.
-		 * On single port, just 0/1 will be used.
-		 */
-		int phyport = i * (sc->sc_numports == 2 ? 2 : 1);
+		uca.bulkin = uca.bulkout = -1;
 
 		ed = usbd_interface2endpoint_descriptor(sc->sc_iface,
 			phyport*2);
 		if (ed == NULL) {
 			aprint_error_dev(self,
-			    "no bulk in endpoint found for %d\n", i);
+			    "no bulk in endpoint found for %d\n", phyport);
 			return;
 		}
 		uca.bulkin = ed->bEndpointAddress;
@@ -332,16 +339,16 @@ umcs7840_attach(device_t parent, device_
 			phyport*2 + 1);
 		if (ed == NULL) {
 			aprint_error_dev(self,
-			    "no bulk out endpoint found for %d\n", i);
+			    "no bulk out endpoint found for %d\n", phyport);
 			return;
 		}
 		uca.bulkout = ed->bEndpointAddress;
-		uca.portno = i;
+		uca.portno = phyport;
 		DPRINTF(("port %d physical port %d bulk-in %d bulk-out %d\n",
 		    i, phyport, uca.bulkin, uca.bulkout));
 
-		sc->sc_ports[i].sc_port_phys = phyport;
-		sc->sc_ports[i].sc_port_ucom =
+		sc->sc_ports[phyport].sc_port_phys = phyport;
+		sc->sc_ports[phyport].sc_port_ucom =
 		    config_found_sm_loc(self, "ucombus", NULL, &uca,
 					    ucomprint, ucomsubmatch);
 	}
@@ -533,8 +540,10 @@ umcs7840_detach(device_t self, int flags
 
 	/* detach children */
 	for (i = 0; i < sc->sc_numports; i++) {
-		if (sc->sc_ports[i].sc_port_ucom) {
-			rv = config_detach(sc->sc_ports[i].sc_port_ucom,
+		int phyport = umcs7840_port2phy(sc, i);
+
+		if (sc->sc_ports[phyport].sc_port_ucom) {
+			rv = config_detach(sc->sc_ports[phyport].sc_port_ucom,
 			    flags);
 			if (rv)
 				break;
@@ -568,8 +577,10 @@ umcs7840_childdet(device_t self, device_
 	int i;
 
 	for (i = 0; i < sc->sc_numports; i++) {
-		if (child == sc->sc_ports[i].sc_port_ucom) {
-			sc->sc_ports[i].sc_port_ucom = NULL;
+		int phyport = umcs7840_port2phy(sc, i);
+
+		if (child == sc->sc_ports[phyport].sc_port_ucom) {
+			sc->sc_ports[phyport].sc_port_ucom = NULL;
 			return;
 		}
 	}
@@ -890,7 +901,9 @@ umcs7840_intr(usbd_xfer_handle xfer, usb
 		uint32_t change_mask = 0;
 		/* Check status of all ports */
 		for (subunit = 0; subunit < sc->sc_numports; subunit++) {
-			uint8_t pn = sc->sc_ports[subunit].sc_port_phys;
+			int phyport = umcs7840_port2phy(sc, subunit);
+			uint8_t pn = sc->sc_ports[phyport].sc_port_phys;
+
 			if (buf[pn] & MCS7840_UART_ISR_NOPENDING)
 				continue;
 			DPRINTF(("Port %d has pending interrupt: %02x "
@@ -930,8 +943,10 @@ umcs7840_change_task(void *arg)
 
 	change_mask = atomic_swap_32(&sc->sc_change_mask, 0);
 	for (i = 0; i < sc->sc_numports; i++) {
-		if (ISSET(change_mask, (1U << i)))
+		int phyport = umcs7840_port2phy(sc, i);
+
+		if (ISSET(change_mask, (1U << phyport)))
 			ucom_status_change(device_private(
-			    sc->sc_ports[i].sc_port_ucom));
+			    sc->sc_ports[phyport].sc_port_ucom));
 	}
 }