revert accidental change

Signed-off-by: Shengliang Xu <shengliangx@nvidia.com>

Author: shengliangxu

modelopt/torch/quantization/config.py

@@ -1560,10 +1560,6 @@ def normalize_quant_cfg_list(v: dict | list) -> list[QuantizerCfgEntry]:
     - An empty entry ``{}``.
     - An entry with only ``quantizer_name`` and no other keys — the only effect would be an
       implicit ``enable=True``, which must be stated explicitly.
-    - An entry with ``enable=True`` (explicit or implicit) whose ``cfg`` is not a non-empty
-      ``dict`` or ``list`` — e.g. ``{"quantizer_name": "*", "cfg": {}}`` or
-      ``{"quantizer_name": "*", "cfg": 42}``.  An enabled quantizer must have a valid
-      configuration.
 
     **Normalization** — after conversion and validation every entry is put into canonical form:
 
@@ -1581,8 +1577,7 @@ def normalize_quant_cfg_list(v: dict | list) -> list[QuantizerCfgEntry]:
 
     Raises:
         ValueError: If any entry has only ``quantizer_name`` with neither ``cfg`` nor ``enable``,
-            if ``enable=True`` with an empty or non-dict/list ``cfg``, or if the entry format
-            is not recognized.
+            or if the entry format is not recognized.
     """
 
     def _warn_legacy():
@@ -1659,12 +1654,6 @@ def _dict_to_entry(key: str, value) -> list[QuantizerCfgEntry]:
             raise ValueError(f"Invalid quant_cfg entry: {raw!r}.")
 
         for entry in entries:
-            # Normalize: empty cfg (empty dict or empty list) carries no information
-            # and is equivalent to no cfg.  Strip it so the validation below can
-            # detect entries that have *neither* cfg nor enable.
-            if "cfg" in entry and isinstance(entry["cfg"], (dict, list)) and len(entry["cfg"]) == 0:
-                del entry["cfg"]
-
             # Validate: must carry at least one instruction beyond the path selector.
             if "cfg" not in entry and "enable" not in entry:
                 raise ValueError(
@@ -1673,28 +1662,6 @@ def _dict_to_entry(key: str, value) -> list[QuantizerCfgEntry]:
                     "enable=True is not allowed; set it explicitly)."
                 )
 
-            # Validate: when cfg is present and enable=True, cfg must be a non-empty
-            # dict or list.  An empty cfg would attempt to create a
-            # QuantizerAttributeConfig with no actual configuration.
-            cfg = entry.get("cfg")
-            enable = entry.get("enable", True)
-            if enable and cfg is not None:
-                if isinstance(cfg, dict):
-                    is_invalid = len(cfg) == 0
-                elif isinstance(cfg, list):
-                    is_invalid = len(cfg) == 0 or any(
-                        not isinstance(item, dict) or len(item) == 0 for item in cfg
-                    )
-                else:
-                    is_invalid = True
-                if is_invalid:
-                    raise ValueError(
-                        f"Invalid quant_cfg entry: {raw!r} — 'cfg' must be a non-empty dict "
-                        f"or a non-empty list of non-empty dicts when enabling a quantizer "
-                        f"(got {type(cfg).__name__}: {cfg!r}). Either provide quantizer "
-                        "attributes in 'cfg' or remove 'cfg' and set 'enable' explicitly."
-                    )
-
             # Normalize: make enable and cfg always explicit.
             entry.setdefault("enable", True)
             entry.setdefault("cfg", None)