fwisound_write_quadlet
err = fwisound_write_quadlet(sc, FWISOUND_REG_SAMPLE_RATE,
err = fwisound_write_quadlet(sc, FWISOUND_REG_ISO_TX_CONFIG, val);
err = fwisound_write_quadlet(sc, FWISOUND_REG_AUDIO_ENABLE,
fwisound_write_quadlet(sc, FWISOUND_REG_AUDIO_ENABLE, 0);
fwisound_write_quadlet(sc, FWISOUND_REG_AUDIO_ENABLE, 0);
fwisound_write_quadlet(sc, FWISOUND_REG_AUDIO_ENABLE, 0);