BWI_RING_ALIGN
.kp_align = BWI_RING_ALIGN,
tx_ring_sz = roundup(desc_sz * BWI_TX_NDESC, BWI_RING_ALIGN);
rx_ring_sz = roundup(desc_sz * BWI_RX_NDESC, BWI_RING_ALIGN);
dma_size = roundup(desc_sz * BWI_TXSTATS_NDESC, BWI_RING_ALIGN);
error = bus_dmamem_alloc(sc->sc_dmat, dma_size, BWI_RING_ALIGN, 0,