VACTIVE_MASK
vactive = REG_FIELD_GET(VACTIVE_MASK, save_vtotal) + 1;
adjusted_mode->crtc_vdisplay = REG_FIELD_GET(VACTIVE_MASK, tmp) + 1;
#define VACTIVE(vdisplay) REG_FIELD_PREP(VACTIVE_MASK, (vdisplay))