Revert "Set default params if missing."

This reverts commit b491fa2

Author: datumbox

torchvision/models/quantization/mobilenetv3.py

@@ -18,8 +18,6 @@
 
 
 class QuantizableSqueezeExcitation(SElayer):
-    _version = 2
-
     def __init__(self, *args: Any, **kwargs: Any) -> None:
         kwargs["scale_activation"] = nn.Hardswish
         super().__init__(*args, **kwargs)
@@ -31,42 +29,6 @@ def forward(self, input: Tensor) -> Tensor:
     def fuse_model(self) -> None:
         fuse_modules(self, ['fc1', 'activation'], inplace=True)
 
-    def _load_from_state_dict(
-        self,
-        state_dict,
-        prefix,
-        local_metadata,
-        strict,
-        missing_keys,
-        unexpected_keys,
-        error_msgs,
-    ):
-        version = local_metadata.get("version", None)
-
-        if version is None or version < 2:
-            default_state_dict = {
-                "scale_activation.activation_post_process.scale": torch.tensor([1.]),
-                "scale_activation.activation_post_process.zero_point": torch.tensor([0], dtype=torch.int32),
-                "scale_activation.activation_post_process.fake_quant_enabled": torch.tensor([1]),
-                "scale_activation.activation_post_process.observer_enabled": torch.tensor([1]),
-                "scale_activation.activation_post_process.activation_post_process.min_val": torch.tensor(float('inf')),
-                "scale_activation.activation_post_process.activation_post_process.max_val": torch.tensor(-float('inf')),
-            }
-            for k, v in default_state_dict.items():
-                full_key = prefix + k
-                if full_key not in state_dict:
-                    state_dict[full_key] = v
-
-        super()._load_from_state_dict(
-            state_dict,
-            prefix,
-            local_metadata,
-            strict,
-            missing_keys,
-            unexpected_keys,
-            error_msgs,
-        )
-
 
 class QuantizableInvertedResidual(InvertedResidual):
     # TODO https://github.com/pytorch/vision/pull/4232#pullrequestreview-730461659
@@ -118,12 +80,13 @@ def _load_weights(
     arch: str,
     model: QuantizableMobileNetV3,
     model_url: Optional[str],
-    progress: bool
+    progress: bool,
+    strict: bool = True
 ) -> None:
     if model_url is None:
         raise ValueError("No checkpoint is available for {}".format(arch))
     state_dict = load_state_dict_from_url(model_url, progress=progress)
-    model.load_state_dict(state_dict)
+    model.load_state_dict(state_dict, strict=strict)
 
 
 def _mobilenet_v3_model(
@@ -147,7 +110,7 @@ def _mobilenet_v3_model(
         torch.quantization.prepare_qat(model, inplace=True)
 
         if pretrained:
-            _load_weights(arch, model, quant_model_urls.get(arch + '_' + backend, None), progress)
+            _load_weights(arch, model, quant_model_urls.get(arch + '_' + backend, None), progress, strict=False)
 
         torch.quantization.convert(model, inplace=True)
         model.eval()