SNDRV_GF1_VB_VOLUME_RATE
snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_RATE, 0x2f);
snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_RATE, 0);
snd_gf1_write8(gus, SNDRV_GF1_VB_VOLUME_RATE, 20); /* ramp rate */