USB: serial: io_ti: verify interrupt endpoint at probe

Verify that the required interrupt endpoint is present at probe rather
than at open to avoid allocating resources for an unusable device.

Note that the endpoint is only required when in download mode.
Signed-off-by: NJohan Hovold <johan@kernel.org>

drivers/usb/serial/io_ti.c

@@ -1933,13 +1933,6 @@ static int edge_open(struct tty_struct *tty, struct usb_serial_port *port)
 	if (edge_serial->num_ports_open == 0) {
 		/* we are the first port to open, post the interrupt urb */
 		urb = edge_serial->serial->port[0]->interrupt_in_urb;
-		if (!urb) {
-			dev_err(&port->dev,
-				"%s - no interrupt urb present, exiting\n",
-				__func__);
-			status = -EINVAL;
-			goto release_es_lock;
-		}
 		urb->context = edge_serial;
 		status = usb_submit_urb(urb, GFP_KERNEL);
 		if (status) {
@@ -2553,7 +2546,8 @@ static int edge_calc_num_ports(struct usb_serial *serial,
 	/* Make sure we have the required endpoints when in download mode. */
 	if (serial->interface->cur_altsetting->desc.bNumEndpoints > 1) {
 		if (epds->num_bulk_in < num_ports ||
-				epds->num_bulk_out < num_ports) {
+				epds->num_bulk_out < num_ports ||
+				epds->num_interrupt_in < 1) {
 			dev_err(dev, "required endpoints missing\n");
 			return -ENODEV;
 		}