[Bugfix] Fix Qwen4Exp PLE embedding rejecting INC (AutoRound) checkpoints

tests/models/qwen4_exp/test_ple.py

@@ -20,6 +20,7 @@
 from vllm.config.compilation import CUDAGraphMode
 from vllm.config.quantization import QuantizationConfigArgs
 from vllm.model_executor.layers.quantization.fp8 import Fp8Config
+from vllm.model_executor.layers.quantization.inc import INCConfig
 from vllm.model_executor.layers.quantization.modelopt import (
     ModelOptMixedPrecisionConfig,
     ModelOptNvFp4Config,
@@ -566,6 +567,24 @@ def test_ple_embedding_respects_modelopt_exclusion() -> None:
     )
 
 
+def test_ple_embedding_respects_inc_layer_config() -> None:
+    prefix = "model.layers.1.ple.ple_embedding.ngram_embedding"
+    quant_config = INCConfig(
+        weight_bits=4,
+        group_size=128,
+        block_name_to_quantize="model.layers",
+        extra_config={".*ple.*": {"bits": 16, "data_type": "float"}},
+    )
+    assert isinstance(
+        Qwen4ExpPLEEmbeddingMethod.from_quant_config(quant_config, prefix),
+        Qwen4ExpPLEUnquantizedEmbeddingMethod,
+    )
+
+    quant_config.extra_config = None
+    with pytest.raises(NotImplementedError, match="INCConfig"):
+        Qwen4ExpPLEEmbeddingMethod.from_quant_config(quant_config, prefix)
+
+
 def test_ple_embedding_dtype_overrides_modelopt_exclusion() -> None:
     prefix = "model.layers.1.ple.ple_embedding.ngram_embedding"
     quant_config = ModelOptNvFp4Config(exclude_modules=[prefix])

vllm/models/qwen4_exp/common/ngram_embedding.py

@@ -27,6 +27,7 @@
     CompressedTensorsConfig,
 )
 from vllm.model_executor.layers.quantization.fp8 import Fp8Config
+from vllm.model_executor.layers.quantization.inc import INCConfig
 from vllm.model_executor.layers.quantization.modelopt import (
     ModelOptMixedPrecisionConfig,
     ModelOptQuantConfigBase,
@@ -190,6 +191,11 @@ def from_quant_config(
             and quant_config.get_scheme_dict(None, layer_name=prefix) is None
         ):
             return Qwen4ExpPLEUnquantizedEmbeddingMethod()
+        if (
+            isinstance(quant_config, INCConfig)
+            and not quant_config.config_parser.resolve(None, prefix).quantized
+        ):
+            return Qwen4ExpPLEUnquantizedEmbeddingMethod()
         if not isinstance(quant_config, Fp8Config):
             raise NotImplementedError(
                 "Qwen4Exp PLE embedding does not support quantization config "