aq_tx_desc
scctx->isc_txqsizes[0] = sizeof(volatile struct aq_tx_desc) * scctx->isc_ntxd[0];
ring->tx_descs = (volatile struct aq_tx_desc*)vaddrs[i];
aq_setup_offloads(struct aq_dev *aq_dev, if_pkt_info_t pi, volatile struct aq_tx_desc *txd,
volatile struct aq_tx_desc *txd = NULL;
txd = (volatile struct aq_tx_desc *)txc;
volatile struct aq_tx_desc *tx_descs;