diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ed9311aaabe7..71dd0305eb32 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1902,6 +1902,9 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
 			sg->length += PAGE_SIZE;
 		}
 		last_pfn = page_to_pfn(page);
+
+		/* Check that the i965g/gm workaround works. */
+		WARN_ON((gfp & __GFP_DMA32) && (last_pfn >= 0x00100000UL));
 	}
 #ifdef CONFIG_SWIOTLB
 	if (!swiotlb_nr_tbl())