mmCRTC_MASTER_UPDATE_MODE
dm_write_reg(tg->ctx, CRTC_REG(mmCRTC_MASTER_UPDATE_MODE), value);
value = dm_read_reg(tg->ctx, CRTC_REG(mmCRTC_MASTER_UPDATE_MODE));
dm_write_reg(tg->ctx, CRTC_REG(mmCRTC_MASTER_UPDATE_MODE), value);
HW_REG_CRTC(mmCRTC_MASTER_UPDATE_MODE, controller_id),
HW_REG_CRTC(mmCRTC_MASTER_UPDATE_MODE, controller_id),