Hi,
Do you design your own custom board or use default board? If you design your own board, you would need to refer to product design guide and adaptation guide for custom USB lane mappings. Please check
https://developer.nvidia.com/embedded/dlc/jetson-tx2-series-oem-product-design-guide
https://developer.nvidia.com/embedded/dlc/Tegra_Linux_Driver_Package_TX2_Adaptation_Guide