drm_rect_calc_vscale
vscale = drm_rect_calc_vscale(src, dst, min_scale, max_scale);
EXPORT_SYMBOL(drm_rect_calc_vscale);
vscale = drm_rect_calc_vscale(&plane_state->base.src,
int drm_rect_calc_vscale(const struct drm_rect *src,