--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -979,8 +979,18 @@ static int dummy_udc_start(struct usb_ga
 	struct dummy_hcd	*dum_hcd = gadget_to_dummy_hcd(g);
 	struct dummy		*dum = dum_hcd->dum;
 
-	if (driver->max_speed == USB_SPEED_UNKNOWN)
+	switch (driver->max_speed) {
+	/* All the speeds we support */
+	case USB_SPEED_LOW:
+	case USB_SPEED_FULL:
+	case USB_SPEED_HIGH:
+	case USB_SPEED_SUPER:
+		break;
+	default:
+		dev_err(dummy_dev(dum_hcd), "bogus driver max_speed %d\n",
+				driver->max_speed);
 		return -EINVAL;
+	}
 
 	/*
 	 * SLAVE side init ... the layer above hardware, which
@@ -1785,7 +1795,8 @@ static void dummy_timer(struct timer_lis
 		total = 490000;
 		break;
 	default:
-		dev_err(dummy_dev(dum_hcd), "bogus device speed\n");
+		dev_err(dummy_dev(dum_hcd), "bogus device speed %d\n",
+				dum->gadget.speed);
 		return;
 	}