igc_adv_tx_desc
union igc_adv_tx_desc *itr_ring;
desc_len = sizeof (union igc_adv_tx_desc) *
val = igc->igc_tx_ndesc * sizeof (union igc_adv_tx_desc);
sizeof (union igc_adv_tx_desc));
union igc_adv_tx_desc *desc;