Index: i915_gem.c
===================================================================
--- i915_gem.c	(revision 293193)
+++ i915_gem.c	(working copy)
@@ -2075,6 +2080,11 @@
 	struct drm_device *dev = obj->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
+	if (obj->base.write_domain & ~I915_GEM_GPU_DOMAINS)
+		DRM_ERROR("obj->base.write_domain & ~I915_GEM_GPU_DOMAINS\n");
+        if (!obj->active)
+		DRM_ERROR("!obj->active\n");
+
 	list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 
 	KASSERT(list_empty(&obj->gpu_write_list), ("On gpu_write_list"));