bwi_txbuf
struct bwi_txbuf *tb = &tbd->tbd_buf[j];
struct bwi_txbuf *tb = &tbd->tbd_buf[i];
struct bwi_txbuf *tb = &tbd->tbd_buf[idx];
struct bwi_txbuf *tb = &tbd->tbd_buf[idx];
struct bwi_txbuf *tb;
struct bwi_txbuf tbd_buf[BWI_TX_NDESC];