DMA_MAX
if (dma < 0 || dma >= DMA_MAX * 2)
dma = DMA_BASE + (branch ? DMA_MAX : 0);
int dma = DMA_MAX + DMA_BASE;
dma_addr_t fdadr[DMA_MAX * 2];
struct pxafb_dma_descriptor dma_desc[DMA_MAX * 2];