tmp = snd_sbmixer_read(chip, 0xc0);
snd_sbmixer_write(chip, 0xc0, tmp|0x80);
/* always select DMA channel 0, since we do not actually use DMA */
snd_sbmixer_write(chip, SB_DSP4_DMASETUP, SB_DMASETUP_DMA0);
snd_sbmixer_write(chip, 0xc0, tmp&0x7f);
tmp = snd_sbmixer_read(chip, 0xc0);
snd_sbmixer_write(chip, 0xc0, tmp|0x80);
/* always select DMA channel 0, since we do not actually use DMA */
snd_sbmixer_write(chip, SB_DSP4_DMASETUP, SB_DMASETUP_DMA0);
snd_sbmixer_write(chip, 0xc0, tmp&0x7f);