the actual change?

src/transformers/modeling_utils.py

@@ -4469,7 +4469,7 @@ class PreTrainedModel(nn.Module, EmbeddingAccessMixin, ModuleUtilsMixin, PushToH
         use_auth_token = kwargs.pop("use_auth_token", None)
         from_pipeline = kwargs.pop("_from_pipeline", None)
         from_auto_class = kwargs.pop("_from_auto", False)
-        dtype = kwargs.pop("dtype", None)
+        dtype = kwargs.pop("dtype", "auto")
         torch_dtype = kwargs.pop("torch_dtype", None)  # kept for BC
         device_map = kwargs.pop("device_map", None)
         max_memory = kwargs.pop("max_memory", None)