greybus: es2: Reserve CPorts 16 and 17

CPorts 16 and 17 are reserved for CDSI0 and CDSI1 by the ES2 APB, make
sure they won't be allocated dynamically.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/es2.c

@@ -841,6 +841,7 @@ static int ap_probe(struct usb_interface *interface,
 	int retval = -ENOMEM;
 	int i;
 	int num_cports;
+	int cport_id;
 
 	udev = usb_get_dev(interface_to_usbdev(interface));
 
@@ -859,6 +860,14 @@ static int ap_probe(struct usb_interface *interface,
 		return PTR_ERR(hd);
 	}
 
+	/*
+	 * CPorts 16 and 17 are reserved for CDSI0 and CDSI1, make sure they
+	 * won't be allocated dynamically.
+	 */
+	do {
+		cport_id = ida_simple_get(&hd->cport_id_map, 16, 18, GFP_KERNEL);
+	} while (cport_id > 0);
+
 	es2 = hd_to_es2(hd);
 	es2->hd = hd;
 	es2->usb_intf = interface;