VDMA_CSR0
csr = viafb_mmio_read(VDMA_CSR0);
viafb_mmio_write(VDMA_CSR0, VDMA_C_DONE);
viafb_mmio_write(VDMA_CSR0, VDMA_C_ENABLE|VDMA_C_DONE);
(void) viafb_mmio_read(VDMA_CSR0);
viafb_mmio_write(VDMA_CSR0, VDMA_C_ENABLE|VDMA_C_START);
if ((viafb_mmio_read(VDMA_CSR0)&VDMA_C_DONE) == 0)
viafb_mmio_write(VDMA_CSR0, VDMA_C_DONE);