diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 6c531abe198b..5a09aff4155a 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -352,6 +352,8 @@ void usbnet_update_max_qlen(struct usbnet *dev)
 {
 	enum usb_device_speed speed = dev->udev->speed;
 
+	if (!dev->rx_urb_size || !dev->hard_mtu)
+		goto insanity;
 	switch (speed) {
 	case USB_SPEED_HIGH:
 		dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
@@ -367,6 +369,7 @@ void usbnet_update_max_qlen(struct usbnet *dev)
 		dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 		break;
 	default:
+insanity:
 		dev->rx_qlen = dev->tx_qlen = 4;
 	}
 }