diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index e06a41b..1f21a9d 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -676,33 +676,29 @@
 	iface_desc = interface->cur_altsetting;
 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 		endpoint = &iface_desc->endpoint[i].desc;
-		
-		if ((endpoint->bEndpointAddress & 0x80) &&
-		    ((endpoint->bmAttributes & 3) == 0x02)) {
+
+		if (usb_endpoint_is_bulk_in(endpoint)) {
 			/* we found a bulk in endpoint */
 			dbg("found bulk in on endpoint %d", i);
 			bulk_in_endpoint[num_bulk_in] = endpoint;
 			++num_bulk_in;
 		}
 
-		if (((endpoint->bEndpointAddress & 0x80) == 0x00) &&
-		    ((endpoint->bmAttributes & 3) == 0x02)) {
+		if (usb_endpoint_is_bulk_out(endpoint)) {
 			/* we found a bulk out endpoint */
 			dbg("found bulk out on endpoint %d", i);
 			bulk_out_endpoint[num_bulk_out] = endpoint;
 			++num_bulk_out;
 		}
-		
-		if ((endpoint->bEndpointAddress & 0x80) &&
-		    ((endpoint->bmAttributes & 3) == 0x03)) {
+
+		if (usb_endpoint_is_int_in(endpoint)) {
 			/* we found a interrupt in endpoint */
 			dbg("found interrupt in on endpoint %d", i);
 			interrupt_in_endpoint[num_interrupt_in] = endpoint;
 			++num_interrupt_in;
 		}
 
-		if (((endpoint->bEndpointAddress & 0x80) == 0x00) &&
-		    ((endpoint->bmAttributes & 3) == 0x03)) {
+		if (usb_endpoint_is_int_out(endpoint)) {
 			/* we found an interrupt out endpoint */
 			dbg("found interrupt out on endpoint %d", i);
 			interrupt_out_endpoint[num_interrupt_out] = endpoint;
@@ -722,8 +718,7 @@
 			iface_desc = dev->actconfig->interface[0]->cur_altsetting;
 			for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 				endpoint = &iface_desc->endpoint[i].desc;
-				if ((endpoint->bEndpointAddress & 0x80) &&
-				    ((endpoint->bmAttributes & 3) == 0x03)) {
+				if (usb_endpoint_is_int_in(endpoint)) {
 					/* we found a interrupt in endpoint */
 					dbg("found interrupt in for Prolific device on separate interface");
 					interrupt_in_endpoint[num_interrupt_in] = endpoint;