AZX_REG_DRSM_CTL
snd_hdac_updatel(bus->drsmcap, AZX_REG_DRSM_CTL, mask, mask);
snd_hdac_updatel(bus->drsmcap, AZX_REG_DRSM_CTL, mask, 0);
bus->drsmcap + AZX_REG_DRSM_CTL);