[Bug]: NVFP4A16 spurious warning that GPU doesn't support Fp4

[mratsim]

Your current environment

The output of python collect_env.py

vLLM API server version 0.11.1rc2.dev200+g250fb1b8e.d20251021

🐛 Describe the bug

When loading a NVFP4A16 quantized model we get a spurious warning

(Worker_TP0 pid=201) WARNING 10-24 09:50:14 [marlin_utils_fp4.py:137] Your GPU does not have native support for FP4 computation but FP4 quantization is being used. Weight-only FP4 compression will be used leveraging the Marlin kernel. This may degrade performance for compute-heavy workloads.

This is using 2x RTX Pro 6000, which do support Fp4.

That warning is coming from

vllm/vllm/model_executor/layers/quantization/utils/marlin_utils_fp4.py

Lines 136 to 142 in 3567816

	def prepare_fp4_layer_for_marlin(layer: torch.nn.Module) -> None:
	logger.warning_once(
	"Your GPU does not have native support for FP4 computation but "
	"FP4 quantization is being used. Weight-only FP4 compression will "
	"be used leveraging the Marlin kernel. This may degrade "
	"performance for compute-heavy workloads."
	)

I believe that warning was supposed to be removed when the emulation path for NVFP4A16 was removed in #18000. If so I can submit a simple PR to remove that part.

Otherwise does it mean there is a new marlin kernel planned that avoids software-dequantizing of NVFP4?

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