public void clearHalt () throws IOException
    {
	if ("bulk" != getType ())
	    throw new IllegalArgumentException ();
	
	// this affects the USB data toggle and other HCD state,
	// otherwise we could issue control requests directly
	if (spi == null)
	    spi = iface.getDevice ().getSPI ();
	spi.clearHalt ((byte) (0x8f & getU8 (2)));
    }