intel: Refuse to do texture tiling if we don't have the kernel support.

src/mesa/drivers/dri/intel/intel_context.c

@@ -731,6 +731,12 @@ intelInitContext(struct intel_context *intel,
    }
    intel->use_texture_tiling = driQueryOptionb(&intel->optionCache,
 					       "texture_tiling");
+   if (intel->use_texture_tiling &&
+       !intel->intelScreen->kernel_exec_fencing) {
+      fprintf(stderr, "No kernel support for execution fencing, "
+	      "disabling texture tiling");
+      intel->use_texture_tiling = GL_FALSE;
+   }
    intel->use_early_z = driQueryOptionb(&intel->optionCache, "early_z");
 
    intel->prim.primitive = ~0;