AC97_THREE_D_CONTROL_REGISTER
ac_mono_set(ctrl, value, AC97_THREE_D_CONTROL_REGISTER, 8);
val = RD(AC97_THREE_D_CONTROL_REGISTER);
WR(AC97_THREE_D_CONTROL_REGISTER, mask);
if ((RD(AC97_THREE_D_CONTROL_REGISTER) & mask) != 0) {
WR(AC97_THREE_D_CONTROL_REGISTER, val);
ac_mono_set(ctrl, value, AC97_THREE_D_CONTROL_REGISTER, 0);