repac_write
sc->sc_achost.write = repac_write;
repac_write(sc, AC97_REG_PCM_FRONT_DAC_RATE, play->sample_rate);
repac_write(sc, AC97_REG_PCM_LR_ADC_RATE, rec->sample_rate);
int repac_write(void *, uint8_t, uint16_t);