USB-C monitor broken in F40 with Intel card

Ask Fedora
1

Hi!

I have a ThinkPad X1 Carbon Gen 9 that has a Intel Corporation TigerLake-LP GT2 [Iris Xe Graphics].
Up to a few weeks ago everything worked properly. I then gave an update (actually a couple, so I lost the last working state :frowning:) and the external monitors on USB-C are not detected anymore.

I use sway, which provides swaymsg -t get_outputs that dump all info on connected outputs, but there is no trace of USB-C monitors. The same monitors attached via HDMI work properly.
I don’t think this is related to Sway, since the issue is already there during boot (while before the update the boot splash screen was appearing on all monitors).

Does anyone experienced this? Any idea on possible ways to further debug it or idea on possible packages to downgrade?

Thanks a lot everyone :slight_smile:
Fale

2

Unplug all but one of those monitors and see what happens, doing the same test with each one to find out if any of them are recognized. It may be that one of them has gone bad, and that’s affected your system’s ability to see the others. If that doesn’t help, try with just one monitor again, but rotate it from one port to the next to see if that makes a change. Let us know the results.

3

Are you using DisplayLink?

% dnf info displaylink
[...]
Installed Packages
Name         : displaylink
Version      : 1.14.6
Release      : 1.github_evdi
Architecture : x86_64
Size         : 15 M
Source       : displaylink-1.14.6-1.github_evdi.src.rpm
Repository   : @System
From repo    : @commandline
Summary      : DisplayLink VGA/HDMI driver for DL-6xxx, DL-5xxx, DL-41xx and DL-3xxx adapters
License      : GPLv2 and LGPLv2 and MIT and ASL 2.0 and Proprietary
Description  : This adds support for HDMI/VGA adapters built upon the DisplayLink DL-7xxx,
             : DL-6xxx, DL-5xxx, DL-41xx and DL-3xxx series of chipsets. This includes
             : numerous docking stations, USB monitors, and USB adapters.

Changes were made in August to support current kernels. Github has Fedora RPM packages and there is also a Fedora copr.

1 Like
4

I have access to 3 USB-C monitors, and I tried to plug/unplug them over and over without any luck.
The interesting thing is that going a dmesg --follow returns the following:

[ 3202.365014] thinkpad_acpi: undocked from hotplug port replicator
[ 3205.806927] thinkpad_acpi: undocked from hotplug port replicator

The interest part is that the first one appeared when I disconnected the USB-C, while the second one when I re-connected it.

5

I did not had it installed, but I tried now to install it without any difference :frowning:

6

I think the problem is that the evdi module is not being loaded in the kernel, probably due to the rpm-ostree installation I have.

I wonder why this change happened mid-cycle, breaking people’s setup…

7

Kernel devs don’t make changes without good reason, but breaking non-free stuff is not unusual. DisplayLink has a “Proprietary” license. EVDI is open source, but only used with DisplayLink. It is left to the Linux community to deal with the changes.

8

I was not referring to the Kernel devs, but to Fedora’s dev that decided to upgrade something mid-release breaking people’s workflow.

Also, a part that is not clear to me is how it is possible that until 6.9 it was working with the Fedora standard kernel, without the need on any proprietary component…

9

OK, that shows that it’s not your monitor. From other replies, it looks like you’ve found the cause, but if you still weren’t sure you could always try plugging something else into the USB ports to show that they’re not bad.

10

In most cases updating the kernel is bring better hardware support and bug fixes. But there are sometime rare regressions, as you found.

It is Fedora policy to update to newer kernels as they are released, after Fedora testing passes.