Hi emersonknapp,
Please following below steps to update firmware:
1.Copy the firmware xusb_sil_rel_fw_1206 to TX2
2.Replace the firmware in initrd image
$ sudo apt-get update
$ sudo apt-get install cpio
$ mkdir initrd_work
$ cd initrd_work
$ sudo cp /boot/initrd ./
$ sudo gunzip -dc ./initrd | sudo cpio -idm
$ sudo rm ./initrd
$ sudo cp <LOCATE OF THE FIRMWARE> ./lib/firmware/tegra18x_xusb_firmware
$ sudo find . | sudo cpio --quiet -H newc -o | sudo gzip -9 -n > ./initrd
$ sudo cp initrd /boot/initrd
3.Reboot the device
$ sudo reboot
xuxb_sil_rel_fw_1206.7z (69.3 KB)