igc_adv_tx_desc
union igc_adv_tx_desc *txdesc = &txr->tx_base[prod];
union igc_adv_tx_desc *txdesc = &txr->tx_base[last];
id * sizeof(union igc_adv_tx_desc), sizeof(union igc_adv_tx_desc),
sizeof(union igc_adv_tx_desc) * sc->num_tx_desc);
sc->num_tx_desc * sizeof(union igc_adv_tx_desc));
union igc_adv_tx_desc *txdesc = &txr->tx_base[id];
sc->num_tx_desc * sizeof(union igc_adv_tx_desc),
txr->tx_base = (union igc_adv_tx_desc *)txr->txdma.dma_vaddr;
union igc_adv_tx_desc *tx_base;