*** ./work/drm-kmod-drm_v5.4.92_2/drivers/gpu/drm/ttm/ttm_bo_vm.c.orig	Thu Feb 11 02:54:13 2021
--- ./work/drm-kmod-drm_v5.4.92_2/drivers/gpu/drm/ttm/ttm_bo_vm.c	Thu Feb 11 02:54:27 2021
***************
*** 313,318 ****
--- 313,320 ----
  			if (bo->mem.bus.is_iomem) {
  				pfn = ttm_bo_io_mem_pfn(bo, page_offset);
  				page = PHYS_TO_VM_PAGE(IDX_TO_OFF(pfn));
+ 				if	(page == NULL)
+ 					goto fail;
  			} else {
  				page = ttm->pages[page_offset];
  				if (page == NULL)