IXGBE_EIAC
IXGBE_WRITE_REG(hw, IXGBE_EIAC, IXGBE_EIMS_RTX_QUEUE);
IXGBE_WRITE_REG(&sc->hw, IXGBE_EIAC, 0);
device_printf(dev, "EIAC:\t%08x\n", IXGBE_READ_REG(hw, IXGBE_EIAC));