I'm running Fedora 39 with no issues on a new Thinkpad Z13 Gen 2 (AMD). If I use a USB-C to DisplayPort cable direct from the computer to the monitor, everything is fine.

I have two symptoms when using the 40B0 dock with it.

1. At boot time, the system will hard lock on the GRUB screen. To work around this, the dock has to be connected after Linux has already booted.
2. No signal is sent to the monitor from the Display Port on the Dock. However, Linux recognizes the display and reports the correct resolution and refresh rate supported by it.

I updated the firmware/bios on both devices out of the box on Friday night. Everything else on the dock seems to work as expected.

Has anyone used this device with Linux successfully? It's only a couple days old, I'll return it if I have to. Hoping it's just a kernel parameter or something simple.

I think I've seen some "linux isn't supported" type replies around this forum, but the solutions page about this device says Fedora 36.

Hello bwcarp.

Welcome to Lenovo Community Forums! 

Apologies for the troubles that you're having with your device. Is this the first time that you're setting up the docking station with your laptop that runs Linux? 

I would recommend trying the following steps:

1. Try using a different DisplayPort cable, if available, to rule out any issues with the cable itself.
2. Check if there are any available updates for your Linux kernel or for the dock itself.
3. Try using the dock with a different device running Fedora 36, if possible, to see if the issue persists.

If none of these steps resolve the issue, please provide us the product number that would look like 21D20000US from the sticker or Vantage app or typing sysinfo in the search box. This will help us to get more details about your machine variant.

Best regards,

Rodney_Lenovo

I upgraded the firmware on the dock to the latest when I received it on Friday. I also received the Z13 that day and found that the BIOS was already up to date.

I am running 6.6.8 Linux kernel which is up to date for Fedora 39.

The display port with this cable worked fine on Windows before I switched to Linux.

To see if it was a regression, I actually tried booting a live session of Fedora 36 (which is mentioned on the info page). F36 is EOL and won't pass secure boot checks on this newer Thinkpad (third party certificate support was already enabled in the bios when I installed 39). I can try booting it with secure boot off if you think it's relevant.

The Thinkpad product number is 21JV000GUS, the dock product number is 40B00135US.

It does, strangely enough, work as expected with my Dell Precision (Intel) laptop running Ubuntu provided by my work. I had purchased it with this Thinkpad trying to keep my personal setup consistent. I tried booting a live image of Ubuntu 22 on the Thinkpad and it also locked up at the GRUB screen.

Reiterating in case it got lost in all this info, the Thinkpad works wonderfully on Fedora when the dock is _not_ plugged in.

You may want to extend your query from the Linux boards here: https://forums.lenovo.com/t5/Linux-Operating-Systems/ct-p/lx_en. 

Best regards,

Rodney_Lenovo

Hello,

I don't use docks.  :(    Does connecting external monitors work without the dock intervening?

Details of what kind of video interface is used via usb c style cables varies between Intel and AMD chipsets.    Is the dock expecting another kind of usb c connection for video?

I hope this helps,

Usedtoberich

I'm not using a USB-C>DisplayPort cable with the dock; the dock is plugged directly into the monitor using it's native display port. It only has problems if the display port is connected, and oddly of the two computers I've used with it, it's specific to the Lenovo (AMD), whereas the Dell (Intel) works fine. The USB-C to Displayport cable is a work around I'm using for now that's plugged directly into the laptop. Everything else about the dock works great.

A new BIOS came out for the computer itself a few days ago that identified a problem with display on this dock, but it hasn't resolved the issue for me. Since the Dell works, I'm thinking it's something with the newer AMD USB4 hardware on Linux. I'm going to compile the 6.7 kernel and see if I have any luck.

Hello,

Especially if the dock connects to your computer with usbC wires, from reading  various  specification sheets for various models, the various ports on your computer have various capability.  Check you are using the correct port for connection, only one of them might have the proper capability.   Also for video over usb C there are a couple of specifications, one is Display Port, and another is Thunder(bird???)   One kind seemed only available on Intel compared to AMD.   And the connection wire is also special for these distinctions compared to one that fits but was found in the back of a closet and has no markings on the cable itself.

If this is not helpful, hopefully someone who knows about docks will respond.

Usedtoberich

Hi,

I've created internal ticket LO-2830 so we can see if we can reproduce; but some notes

I'm using the TBT4 dock with my P14s G4 AMD and Fedora39 - which is the same CPU family so I would expect it to work. Only caveat is my monitor is on HDMI - so I'll see if I can switch to Display Port and try that. If you are able to test with HDMI that might be interesting.

I've asked my colleague to test with Z13 G2. That is a certified with Ubuntu and Fedora (www.lenovo.com/linux) - but we don't do dock testing by default (we have done a lot of dock testing separately - but it's not part of the core certification).

I assume no error messages in the kernel logs (journalctl -k)?

Mark

I don't know why I hadn't tried HDMI until now, but HDMI appears to work just fine with the same dock, monitor and computer. So we have isolated it to display port.

I'm short on time but I can try to dig through logs with DP connected later. As it is I can advise that it will lock upon making a selection from the GRUB screen with DP connected.

Hello @bwcarp

I have tested on Fedora 39 with the latest BIOS 37w and EC 34w, using TBT4 USB cable. I cannot reproduce the issue with HDMI and both DP ports on the dock it's working fine. What kind of TBT USB cable are you using for you Dock, is it TBT3 or TBT4?

Thanks,