Serial port driver of nvidia jetson xavier nx is dma mode transmission

May I ask if the current serial port driver of nvidia jetson xavier nx is dma mode transmission, if not, how to modify the serial port driver to satisfy

Hi,
The base setting is in

hardware/nvidia/soc/t19x/kernel-dts/tegra194-soc/tegra194-soc-uart.dtsi

It is dma mode by default since all uart ports have the setting like:

                dmas = <&gpcdma 8>, <&gpcdma 8>;
                dma-names = "rx", "tx";

thank u,In addition, what is the buffer size of the serial port in dma mode?

Hi,
For more information, please check section 10.4 in technical reference manual. The document is in download center:
Jetson Download Center | NVIDIA Developer

Xavier Series SoC Technical Reference Manual