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The motivation is to allow userspace to choose between lower latency and higher throughput at runtime. Some latency-sensitive request/response deployments become unreliable if the UART FIFO is enabled due to the added buffering delay. I understand the concern about driver-specific sysfs knobs. UART FIFO enable/disable seems more like a common UART capability than a device-unique behaviour. If a driver-specific sysfs attribute is not the right approach here, do you have a suggestion for a better interface? --- Sincerely, Crescent Hsieh