static int
get_back_bo(struct dri2_egl_surface *dri2_surf)
{
   struct dri2_egl_display *dri2_dpy =
      dri2_egl_display(dri2_surf->base.Resource.Display);
   struct gbm_dri_surface *surf = dri2_surf->gbm_surf;
   int age = 0;

   if (dri2_surf->back == NULL) {
      printf("--panfrost: look for new backbuffer... %i to pick from\n", (int)ARRAY_SIZE(dri2_surf->color_buffers));
      for (unsigned i = 0; i < ARRAY_SIZE(dri2_surf->color_buffers); i++) {
         printf("--panfrost:   buf [%p] %i locked=%i, age=%i\n", dri2_surf->color_buffers[i].bo, i, dri2_surf->color_buffers[i].locked, dri2_surf->color_buffers[i].age);
         if (!dri2_surf->color_buffers[i].locked &&
              dri2_surf->color_buffers[i].age >= age) {
            dri2_surf->back = &dri2_surf->color_buffers[i];
            age = dri2_surf->color_buffers[i].age;
            printf("--panfrost:     chosen [%p] age=%i\n", dri2_surf->back->bo, age);
         }
      }
   }

   if (dri2_surf->back == NULL)
      return -1;
   if (dri2_surf->back->bo == NULL) {
      if (surf->base.modifiers)
         dri2_surf->back->bo = gbm_bo_create_with_modifiers(&dri2_dpy->gbm_dri->base,
                                                            surf->base.width,
                                                            surf->base.height,
                                                            surf->base.format,
                                                            surf->base.modifiers,
                                                            surf->base.count);
      else
         dri2_surf->back->bo = gbm_bo_create(&dri2_dpy->gbm_dri->base,
                                             surf->base.width,
                                             surf->base.height,
                                             surf->base.format,
                                             surf->base.flags);

      printf("--panfrost: had to create new buffer %p\n", dri2_surf->back->bo);
   }
   if (dri2_surf->back->bo == NULL)
      return -1;

   return 0;
}