[LoRA] Guard TMA down path for LoRA hooks (#31608)

python/sglang/srt/layers/moe/moe_runner/triton_utils/fused_moe.py

@@ -473,6 +473,12 @@ def _fused_moe_kernel_sequence(
     topk = topk_ids.shape[1]
     compute_type = tl.bfloat16 if hidden_states.dtype == torch.bfloat16 else tl.float16
 
+    # LoRA hooks consume and update route-major intermediate buffers. The TMA
+    # down path keeps those buffers in expert-sorted, block-padded order, which
+    # is incompatible with the hook contract.
+    if hooks and (hooks.after_gate_up is not None or hooks.after_down is not None):
+        down_moe_use_tma = False
+
     padded_tokens = (
         min(num_tokens * topk, E + 1) * (config["BLOCK_SIZE_M"] - 1)
         if down_moe_use_tma