[AMD] Clamp MORI intranode grid GPUs (#39763)

Co-authored-by: Duyi-Wang <duyi.wang@amd.com>

python/sglang/srt/layers/moe/token_dispatcher/moriep.py

@@ -319,6 +319,15 @@ def init_mori_op(
                 block_num = 256
                 warp_num_per_block = 16
 
+    if kernel_type == mori.ops.EpDispatchCombineKernelType.IntraNode:
+        # mori's intranode combine ends in a grid-wide barrier every block spins
+        # on. A 256-block grid deadlocks on a 192-CU device; clamping to the CU
+        # count is a conservative bound, not the measured residency limit.
+        cu_count = torch.cuda.get_device_properties(
+            torch.cuda.current_device()
+        ).multi_processor_count
+        block_num = min(block_num, cu_count)
+
     # Fp8 blockwise combine uses its own internal scale_dim driven which can be
     # overridden by env ``MORI_FP8_COMBINE_SCALE_DIM`` (default 56)
     # See https://github.com/ROCm/mori/blob/96ffa169710f214e76e07abe5008d686fe54522b/python/mori/ops/dispatch_combine.py#L81-L84