drm_helper_crtc_mode_set_base
ret = drm_helper_crtc_mode_set_base(crtc, x, y, old_fb);
EXPORT_SYMBOL(drm_helper_crtc_mode_set_base);
int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,