B43_DMA32_RXCTL
ctl = b43_read32(dev, mmio_base + B43_DMA32_RXCTL);
b43_write32(dev, mmio_base + B43_DMA32_RXCTL, ctl);
offset = (type == B43_DMA_64BIT) ? B43_DMA64_RXCTL : B43_DMA32_RXCTL;
b43_dma_write(ring, B43_DMA32_RXCTL, value);