USB: usblp: refactor endpoint retrieval

Use the new endpoint helpers to lookup the required bulk-out endpoint
and the depending on protocol likewise required bulk-in endpoint.

Cc: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/class/usblp.c

@@ -1239,8 +1239,9 @@ static int usblp_select_alts(struct usblp *usblp)
 {
 	struct usb_interface *if_alt;
 	struct usb_host_interface *ifd;
-	struct usb_endpoint_descriptor *epd, *epwrite, *epread;
-	int p, i, e;
+	struct usb_endpoint_descriptor *epwrite, *epread;
+	int p, i;
+	int res;
 
 	if_alt = usblp->intf;
 
@@ -1260,31 +1261,21 @@ static int usblp_select_alts(struct usblp *usblp)
 		    ifd->desc.bInterfaceProtocol > USBLP_LAST_PROTOCOL)
 			continue;
 
-		/* Look for bulk OUT and IN endpoints. */
-		epwrite = epread = NULL;
-		for (e = 0; e < ifd->desc.bNumEndpoints; e++) {
-			epd = &ifd->endpoint[e].desc;
-
-			if (usb_endpoint_is_bulk_out(epd))
-				if (!epwrite)
-					epwrite = epd;
-
-			if (usb_endpoint_is_bulk_in(epd))
-				if (!epread)
-					epread = epd;
+		/* Look for the expected bulk endpoints. */
+		if (ifd->desc.bInterfaceProtocol > 1) {
+			res = usb_find_common_endpoints(ifd,
+					&epread, &epwrite, NULL, NULL);
+		} else {
+			epread = NULL;
+			res = usb_find_bulk_out_endpoint(ifd, &epwrite);
 		}
 
 		/* Ignore buggy hardware without the right endpoints. */
-		if (!epwrite || (ifd->desc.bInterfaceProtocol > 1 && !epread))
+		if (res)
 			continue;
 
-		/*
-		 * Turn off reads for USB_CLASS_PRINTER/1/1 (unidirectional)
-		 * interfaces and buggy bidirectional printers.
-		 */
-		if (ifd->desc.bInterfaceProtocol == 1) {
-			epread = NULL;
-		} else if (usblp->quirks & USBLP_QUIRK_BIDIR) {
+		/* Turn off reads for buggy bidirectional printers. */
+		if (usblp->quirks & USBLP_QUIRK_BIDIR) {
 			printk(KERN_INFO "usblp%d: Disabling reads from "
 			    "problematic bidirectional printer\n",
 			    usblp->minor);