E1000_TXD_CMD_DEXT
*txd_lower = (E1000_TXD_CMD_DEXT | /* Extended descr type */
E1000_TXD_CMD_DEXT | /* Extended descr */
*txd_lower = E1000_TXD_CMD_DEXT | E1000_TXD_DTYP_D;
htole32(E1000_TXD_CMD_IFCS | E1000_TXD_CMD_DEXT | cmd);