[PATCH] USB speedtouch: add defensive memory barriers

Defend against future maintainers.

drivers/usb/misc/speedtch.c

@@ -1228,6 +1228,7 @@ static int udsl_usb_probe (struct usb_interface *intf, const struct usb_device_i
 
 finish:
 	/* ready for ATM callbacks */
+	wmb ();
 	instance->atm_dev->dev_data = instance;
 
 	usb_set_intfdata (intf, instance);
@@ -1366,6 +1367,7 @@ static void udsl_usb_disconnect (struct usb_interface *intf)
 	for (i = 0; i < UDSL_NUMBER_SND_BUFS; i++)
 		kfree (instance->all_buffers[i].base);
 
+	wmb ();
 	instance->usb_dev = NULL;
 
 	/* atm finalize */