Ubuntu 22.04 does not restore the screen on a KVM switch

[Peter da Silva]

Ubuntu 22.04 on either of two HP small business PC.

1. an HP EliteDesk 800 G3 Mini PC with an i915 video controller using Displayport to HDMI.
2. an HP 600 G1 desktop SFF with an i915 video controller, also using Displayport to HDMI.

Both are connected to a KVM switch.

When I boot up I get a login and everything works fine, until I switch between them. No image appears. There is a slight brightening of the display after a few seconds, as if it's trying to enable video output, but I have to unplug and replug the displayport connector at the back of the computer to get the screen to come back.

journalctl -k shows these lines logged on the HP 600 G1:

Apr 04 20:55:42 demesne kernel: i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20
Apr 04 20:55:42 demesne kernel: i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20

on the EliteDesk 800 G3, the same message:

Apr 04 20:55:58 haven kernel: i915 0000:00:02.0: [drm] *ERROR* Unexpected DP dual mode adaptor ID 20

https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-5.19/+filebug/e70d8b1a-d357-11ed-b7a8-d485646cd9a4?
https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-5.19/+filebug/26e2b774-d358-11ed-99a2-40a8f0305cb4?

Both systems are Ubuntu 22.04.2 LTS
---
ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu82.3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: peter 1719 F.... pulseaudio
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
DistroRelease: Ubuntu 22.04
InstallationDate: Installed on 2023-04-05 (0 days ago)
InstallationMedia: Ubuntu 22.04.2 LTS "Jammy Jellyfish" - Release amd64 (20230223)
MachineType: HP HP EliteDesk 800 G3 DM 35W
Package: linux (not installed)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.19.0-38-generic root=UUID=69e670cd-6996-4cc1-bdb0-bdc9e857503e ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 5.19.0-38.39~22.04.1-generic 5.19.17
RelatedPackageVersions:
 linux-restricted-modules-5.19.0-38-generic N/A
 linux-backports-modules-5.19.0-38-generic N/A
 linux-firmware 20220329.git681281e4-0ubuntu3.12
Tags: wayland-session jammy
Uname: Linux 5.19.0-38-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin lxd plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 04/27/2020
dmi.bios.release: 2.34
dmi.bios.vendor: HP
dmi.bios.version: P21 Ver. 02.34
dmi.board.name: 829A
dmi.board.vendor: HP
dmi.board.version: KBC Version 06.29
dmi.chassis.type: 35
dmi.chassis.vendor: HP
dmi.ec.firmware.release: 6.41
dmi.modalias: dmi:bvnHP:bvrP21Ver.02.34:bd04/27/2020:br2.34:efr6.41:svnHP:pnHPEliteDesk800G3DM35W:pvr:rvnHP:rn829A:rvrKBCVersion06.29:cvnHP:ct35:cvr:sku4DS57UC#ABA:
dmi.product.family: 103C_53307F HP EliteDesk
dmi.product.name: HP EliteDesk 800 G3 DM 35W
dmi.product.sku: 4DS57UC#ABA
dmi.sys.vendor: HP

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 2015314

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

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[Peter da Silva (resuna)]

LOL I had to go back and fiddle with the console cable to get the screen back so I could run apport-collect because it requires both browser and GUI integration.

[Peter da Silva (resuna)]

Edit: changed status to confirmed as per instructions from the bot message.

[Daniel Wroblewski (danielagw)]

I am experiencing the same issue. I have two laptops, one MacBook Air and one Dell Inspiron with Ubuntu 22.04. I constantly need to switch the monitor between these two. I have an HDMI switcher which used to work great on Ubuntu 20.04. But now with Ubuntu 22.04 it is not possible. Ubuntu is able to display the picture on the monitor only after plugging the HDMI in. After I switch to Mac, I am unable to switch back to Ubuntu.

I guess this must have something to do with how KVM and HDMI switchers work. Maybe they don't disconnect the inactive device entirely and, as a result, switching back to Ubuntu does not trigger the same behavior that connecting the HDMI cable does? It's important to note that after switching the HDMI from Ubuntu to Mac, Ubuntu is fully aware that HDMI has been disconnected and the external monitor is not detected. But still it never gets detected again.