[Bug] Fix Assertion error DeepEP/csrc/kernels/intranode.cu:928: 'false and Unsupported type' (#26532)

Signed-off-by: yewentao256 <zhyanwentao@126.com>

Author: yewentao256

vllm/model_executor/layers/fused_moe/deepep_ht_prepare_finalize.py

@@ -336,7 +336,11 @@ def _finalize(
                 apply_router_weight_on_input=apply_router_weight_on_input,
             )
         dbo_yield_and_switch_from_compute_to_comm()
+        assert fused_expert_output.dtype == torch.bfloat16, (
+            f"Expected fused_expert_output bfloat16, got {fused_expert_output.dtype}"
+        )
         combined_x, _, event = self.buffer.combine(
+            # HT combine only supports BF16
             x=fused_expert_output,
             handle=handle,
             topk_weights=None,

vllm/model_executor/layers/fused_moe/modular_kernel.py

@@ -984,7 +984,7 @@ def input_chunk_range(chunk_idx: int) -> tuple[int, int]:
             assert num_chunks == 0
             workspace13 = None
             workspace2 = None
-            fused_out = torch.empty_like(a1q)
+            fused_out = torch.empty_like(a1q, dtype=in_dtype)
         else:
             assert num_chunks > 0
             workspace13, workspace2, fused_out = self._allocate_buffers(