Fix circular import in quantization modules (#17372)

python/sglang/srt/layers/linear.py

@@ -31,7 +31,6 @@ from sglang.srt.layers.parameter import (
     RowvLLMParameter,
     _ColumnvLLMParameter,
 )
-from sglang.srt.layers.quantization.unquant import UnquantizedLinearMethod
 from sglang.srt.layers.utils import pad_or_narrow_weight
 from sglang.srt.utils import get_bool_env_var, is_cpu, is_hip, is_npu, set_weight_attrs
 
@@ -165,6 +164,8 @@ class LinearBase(torch.nn.Module):
         self.params_dtype = params_dtype
         self.quant_config = quant_config
         if quant_config is None:
+            from sglang.srt.layers.quantization.unquant import UnquantizedLinearMethod
+
             self.quant_method: Optional[QuantizeMethodBase] = UnquantizedLinearMethod()
         else:
             self.quant_method = quant_config.get_quant_method(self, prefix=prefix)

python/sglang/srt/layers/quantization/auto_round.py

@@ -13,8 +13,6 @@ from sglang.srt.layers.quantization.utils import get_scalar_types
 
 ScalarType, scalar_types = get_scalar_types()
 
-
-from sglang.srt.layers.linear import LinearBase, UnquantizedLinearMethod
 from sglang.srt.layers.quantization.base_config import QuantizationConfig
 
 
@@ -217,11 +215,13 @@ class AutoRoundConfig(QuantizationConfig):
         return weight_bits < 16
 
     def apply_awq_quant_layer(self, layer, prefix: str, backend: str = "auto"):
+        from sglang.srt.layers.linear import LinearBase
         from sglang.srt.layers.moe.fused_moe_triton import FusedMoE
         from sglang.srt.layers.quantization.marlin_utils import (
             check_marlin_supported,
             check_moe_marlin_supports_layer,
         )
+        from sglang.srt.layers.quantization.unquant import UnquantizedLinearMethod
         from sglang.srt.layers.vocab_parallel_embedding import ParallelLMHead
 
         weight_bits, group_size, sym = self.get_layer_config(layer, prefix)
@@ -299,11 +299,13 @@ class AutoRoundConfig(QuantizationConfig):
         return None
 
     def apply_gptq_quant_layer(self, layer, prefix: str, backend: str = "auto"):
+        from sglang.srt.layers.linear import LinearBase
         from sglang.srt.layers.moe.fused_moe_triton import FusedMoE
         from sglang.srt.layers.quantization.marlin_utils import (
             check_marlin_supported,
             check_moe_marlin_supports_layer,
         )
+        from sglang.srt.layers.quantization.unquant import UnquantizedLinearMethod
         from sglang.srt.layers.vocab_parallel_embedding import ParallelLMHead
 
         weight_bits, group_size, sym = self.get_layer_config(layer, prefix)

python/sglang/srt/layers/quantization/petit.py

@@ -8,7 +8,7 @@ import regex as re
 import torch
 from torch.nn.parameter import Parameter
 
-from sglang.srt.layers.linear import LinearBase, UnquantizedLinearMethod
+from sglang.srt.layers.linear import LinearBase
 from sglang.srt.layers.parameter import ModelWeightParameter, PerTensorScaleParameter
 from sglang.srt.layers.quantization.base_config import (
     LinearMethodBase,
@@ -20,6 +20,7 @@ from sglang.srt.layers.quantization.petit_utils import (
     prepare_nvfp4_layer_for_petit,
     verify_petit_nvfp4_supported,
 )
+from sglang.srt.layers.quantization.unquant import UnquantizedLinearMethod
 from sglang.srt.layers.quantization.utils import is_layer_skipped
 from sglang.srt.utils import is_hip
 

python/sglang/srt/layers/quantization/quark/quark.py

@@ -6,7 +6,7 @@ from typing import Any, List, Optional, cast
 
 import torch
 
-from sglang.srt.layers.linear import LinearBase, UnquantizedLinearMethod
+from sglang.srt.layers.linear import LinearBase
 from sglang.srt.layers.quantization.base_config import (  # noqa: E501
     LinearMethodBase,
     QuantizationConfig,
@@ -20,6 +20,7 @@ from sglang.srt.layers.quantization.quark.schemes import (
     QuarkW8A8Fp8,
 )
 from sglang.srt.layers.quantization.quark.utils import deep_compare, should_ignore_layer
+from sglang.srt.layers.quantization.unquant import UnquantizedLinearMethod
 from sglang.srt.layers.radix_attention import RadixAttention
 from sglang.srt.utils import get_device_capability
 

python/sglang/srt/layers/quantization/w4afp8.py

@@ -7,7 +7,6 @@ import torch
 from torch.nn import Module
 from torch.nn.parameter import Parameter
 
-from sglang.srt.layers.linear import UnquantizedLinearMethod
 from sglang.srt.layers.quantization.base_config import (
     FusedMoEMethodBase,
     QuantizationConfig,