ESSSB_IREG_AUDIO2CONTROL2
snd_es1938_mixer_bits(chip, ESSSB_IREG_AUDIO2CONTROL2, 0x80, 0);
snd_es1938_mixer_write(chip, ESSSB_IREG_AUDIO2CONTROL2, 0x40 | (u ? 0 : 4) |