XPS15 9550双系统下Ubuntu雷电3扩展坞USB及网口失效求助

Hey Nathan, let's tackle this Thunderbolt 3 dock issue on your Ubuntu 16.04 setup. I've seen similar headaches with Dell XPS models and third-party docks, so here are targeted steps to diagnose and fix the USB/Ethernet functionality:

1. Fix Thunderbolt 3 Authorization Permissions #

Ubuntu's default Thunderbolt security settings often block non-display peripherals on docks. Let's adjust this:

• Open Settings > Devices > Thunderbolt (if you don't see this menu, install the required tools first with sudo apt install thunderbolt-tools)
• Locate your dock in the device list and set its permission level to Authorize All Devices or No Security
• Alternatively, use the command line to authorize it directly:

  # List all connected Thunderbolt devices to get the dock's ID
  boltctl list
  # Replace <dock-id> with the ID from the output above
  sudo boltctl authorize <dock-id>
  

2. Update Your Kernel (Critical for Thunderbolt 3 Support) #

Your current 4.15.3 kernel is outdated, and Thunderbolt 3 compatibility improved drastically in later 4.15.x updates. Let's install the latest stable kernel for 16.04:

sudo apt update
sudo apt install --install-recommends linux-generic-hwe-16.04

Reboot your system, then verify the new kernel version with uname -r (it should show something like 4.15.0-213-generic).

3. Refresh USB/Ethernet Drivers #

Let's ensure the system recognizes the dock's controllers and reload their drivers:

• Run lsusb in the terminal and check for entries related to your dock (look for "USB hub" or "Ethernet controller" that appears only when the dock is connected)
• For Ethernet, reload the common Thunderbolt dock driver with:

  sudo modprobe -r r8152 && sudo modprobe r8152
  

  (If your dock uses a different Ethernet chipset, adjust the module name to match what you see in lspci | grep Ethernet.)

4. Disable Secure Boot #

Secure Boot frequently interferes with Thunderbolt 3 device drivers on Ubuntu:

• Reboot your XPS 15 and press F2 to enter BIOS/UEFI setup
• Navigate to the Security tab and disable Secure Boot
• Save changes and reboot back into Ubuntu, then test the dock's ports again.

5. Rule Out a Faulty Cable (Optional) #

Non-certified or damaged Thunderbolt 3 cables can cause partial functionality issues. If you have another certified cable handy, swap it to see if that resolves the problem.

If none of these steps work, share the output of boltctl list and lsusb (with the dock connected) and we can dig into more specific troubleshooting.

内容的提问来源于stack exchange，提问作者Nathan.K