Two external monitors garbled on newer kernels than 5.19
| Affects | Status | Importance | Assigned to | Milestone | |
|---|---|---|---|---|---|
| linux-signed-hwe-6.2 (Ubuntu) |
Confirmed
|
Undecided
|
Unassigned | ||
Bug Description
Hardware: Lenovo ThinkPad model 20ST0055AU
Description: Ubuntu 22.04.2 LTS
Release: 22.04
Kernel: 6.2.0-26-generic #26~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Jul 13 16:27:29 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
What I expected to happen:
Using Lenovo dock via Thunderbolt connector, and with two DisplayPort monitors connected for three monitors in total. Display should be usable, and in fact _does_ work with 5.19.
What happened instead:
When attempting to use any ubuntu kernel > 5.19 I have had garbled output on the DisplayPort monitors.
I've checked on a few 6.2.0 kernels as have come through as part of linux-image-
I've attached a picture taken with my phone on bootup while prompted for the disk encryption password.
The GUI also displays in a similar garbled fashion if I let it boot further and is unusable.
This happens on a Lenovo thunderbolt dock (which was actively attached when producing the lspci and lsusb output attached here), but I've also confirmed this issue occurs on a Dell WD19TB thunderbolt dock with 1xHDMI connection as well.
| Kamikaze (mick-saunders) wrote | #1 |
| affects: | linux-signed-oem-5.14 (Ubuntu) → linux-meta-hwe-6.2 (Ubuntu) |
| affects: | linux-meta-hwe-6.2 (Ubuntu) → linux-signed-hwe-6.2 (Ubuntu) |
| Kamikaze (mick-saunders) wrote | #2 |
| description: | updated |
| Josef Cacek (josef-cacek) wrote | #4 |
| Launchpad Janitor (janitor) wrote | #5 |
| Changed in linux-signed-hwe-6.2 (Ubuntu): | |
| status: | New → Confirmed |
I have the same issue with my Lenovo Thinkpad P1 Gen3 + ThinkPad Thunderbolt 3 Workstation Dock Gen 2.
With 5.19 kernels displays work properly; with 6.2 the 2 external monitors are garbled.