correct the tp_plan logic (#8850)

python/sglang/srt/models/transformers.py

@@ -211,16 +211,13 @@ class TransformersForCausalLM(nn.Module):
         Apply the model's tensor parallelization plan.
         Currently only supports linear layers.
         """
-        if not self.model.supports_tp_plan:
-            if tp_size <= 1:
-                return
+        tp_plan = getattr(self.model.config, "base_model_tp_plan", None) or {}
 
+        if not tp_plan and self.tp_size > 1:
             raise ValueError(
                 f"{type(self.model)} does not support tensor parallel yet!"
             )
 
-        tp_plan = getattr(self.model.config, "base_model_tp_plan", None) or {}
-
         def _tensor_parallel(module: nn.Module, prefix: str = ""):
             for child_name, child_module in module.named_children():
                 qual_name = maybe_prefix(prefix, child_name)