ENVY24_ROUTE_DAC_SPDIF
if (dac < 0 || ENVY24_ROUTE_DAC_SPDIF < dac)
(dac != ENVY24_ROUTE_DAC_1 && dac != ENVY24_ROUTE_DAC_SPDIF))
if (dac == ENVY24_ROUTE_DAC_SPDIF) {
envy24_route(sc, ENVY24_ROUTE_DAC_SPDIF, ENVY24_ROUTE_CLASS_DMA, 0, 0);