[PATCH] scanner.c: Accept scanners with more than one interface

This patch allows the scanner driver to accept devices with more than
one interface. That's needed by some multi-function periphals (e.g.
scanner+printer).

drivers/usb/image/scanner.c

@@ -325,6 +325,8 @@
  *    - Some Benq, Genius and Plustek ids are identified now.
  *    - Accept scanners with only one bulk (in) endpoint (thanks to Sergey
  *      Vlasov <vsu@mivlgu.murom.ru>).
+ *    - Accept devices with more than one interface. Only use interfaces that
+ *      look like belonging to scanners.
  *
  * TODO
  *    - Remove the 2/3 endpoint limitation
@@ -907,13 +909,15 @@ probe_scanner(struct usb_interface *intf,
 		return -ENODEV;
 	}
 
-	if (dev->config[0].desc.bNumInterfaces != 1) {
-		info("probe_scanner: Only one device interface is supported.");
+	interface = intf->altsetting;
+ 
+	if (interface[0].desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC &&
+	    interface[0].desc.bInterfaceClass != USB_CLASS_PER_INTERFACE &&
+	    interface[0].desc.bInterfaceClass != 16) {
+		dbg("probe_scanner: This interface doesn't look like a scanner (class=0x%x).", interface[0].desc.bInterfaceClass);
 		return -ENODEV;
 	}
 
-	interface = intf->altsetting;
-
 /*
  * Start checking for one or two bulk endpoints and an optional
  * interrupt endpoint. If we have an interrupt endpoint go ahead and