XPS 13-9360, TB3/USB Type-C, stopped working

Is this XPS 13-9360 still under warranty? Click my DELL-name and private message me the service tag number so I can check.

Check this thread: https://www.dell.com/community/Linux-General/Dell-XPS-13-9380-Thunderbolt-3-USB-Type-C-stopped-working/m-p/7248637#M16606

(Ignore the official "solution", it does not work. But turning it off and back on seems to temporary fix issues.)

The latest XPS_9360_2.12.0.exe has fixed this issue thankfully, but the wired ethernet adapter included in the DA300 still doesn't work reliably. I will see if I can down-grade to firmware from 2 years ago and hope that helps.

If the system DOES NOT have Thunderbolt 3 capability, the thunderbolt options will be grayed out and cannot be selected in the BIOS.  

There are security settings for thunderbolt3

Starting with Intel Falcon Ridge Thunderbolt controller there are 4 security levels available. Intel Titan Ridge added one more security level (usbonly). The reason for these is the fact that the connected devices can be DMA masters and thus read contents of the host memory without CPU and OS knowing about it. There are ways to prevent this by setting up an IOMMU but it is not always available for various reasons.

https://www.kernel.org/doc/html/latest/admin-guide/thunderbolt.html

must be set to none for linux because there is no OS level support for the "authorized by OS" mode.

there is an experimental package BOLT

sudo apt install bolt

THUNDERBOLT AND UBUNTU

Thunderbolt 3 — supports different security levels:

none: No security. The behavior is identical to previous Thunderbolt 1 and 2 versions.

dponly: No PCIe tunnels are created at all, but DisplayPort tunnels are allowed and will work.

user: Connected devices must be authorized by the user. Only then will the PCIe tunnels be activated.

secure: Basically the same as user mode, but additionally a key will be written to the device the first time the device is connected. This key will then be used to verify the identity of the connected device.

The security levels are as follows:

none All devices are automatically connected by the firmware. No user approval is needed. In BIOS settings this is typically called Legacy mode. user User is asked whether the device is allowed to be connected. Based on the device identification information available through /sys/bus/thunderbolt/devices, the user then can make the decision. In BIOS settings this is typically called Unique ID. secure User is asked whether the device is allowed to be connected. In addition to UUID the device (if it supports secure connect) is sent a challenge that should match the expected one based on a random key written to the key sysfs attribute. In BIOS settings this is typically called One time saved key. dponly The firmware automatically creates tunnels for Display Port and USB. No PCIe tunneling is done. In BIOS settings this is typically called Display Port Only. usbonly The firmware automatically creates tunnels for the USB controller and Display Port in a dock. All PCIe links downstream of the dock are removed.

The current security level can be read from /sys/bus/thunderbolt/devices/domainX/security where domainX is the Thunderbolt domain the host controller manages. There is typically one domain per Thunderbolt host controller.