Screen restarts and logs out when disconnecting HDMI cable

Bug #2068904 reported by Anne Chew Yii Huei
This bug affects 1 person
Affects Status Importance Assigned to Milestone
ubuntu-meta (Ubuntu)

Bug Description

Replication steps:

1. Start up Ubuntu desktop as usual with HDMI cable connected to external monitor in extended desktop mode.
2. Log in to Ubuntu desktop.
3. Launch a few applications (e.g. browser, terminal, etc).
4. Disconnect HDMI cable.

Expected behaviour:

Desktop session should still be available on laptop screen after disconnecting HDMI cable.

Current behaviour:

Laptop screen goes black and shows the login screen. Logging in again shows a fresh desktop session (no open application windows).

Other information:

This is a dual-OS machine, with home directory encryption enabled for Ubuntu.
Installed from Mantic originally, and upgraded to Noble via command line.

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: ubuntu-desktop 1.539
ProcVersionSignature: Ubuntu 6.5.0-35.35-generic 6.5.13
Uname: Linux 6.5.0-35-generic x86_64
ApportVersion: 2.28.1-0ubuntu3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Jun 10 21:51:29 2024
EcryptfsInUse: Yes
InstallationDate: Installed on 2024-03-14 (88 days ago)
InstallationMedia: Ubuntu Legacy 23.10 "Mantic Minotaur" - Release amd64 (20231010)
SourcePackage: ubuntu-meta
UpgradeStatus: No upgrade log present (probably fresh install)

Revision history for this message
Anne Chew Yii Huei (annecyh) wrote :
Revision history for this message
AceLan Kao (acelankao) wrote :

Looks like the X or Wayland crashes when HDMI cable is unplugged.

We may need below logs
1. dmesg with drm.debug=0x1e
2. sudo lspci -vvnn

Revision history for this message
Anne Chew Yii Huei (annecyh) wrote :

dmesg output with drm.debug=0x1e

Revision history for this message
Anne Chew Yii Huei (annecyh) wrote :

output for "sudo lspci -vvnn" after reproducing the issue and logging back in.

Revision history for this message
AceLan Kao (acelankao) wrote :

It's the gnome-shell crashes.

[86941.402557] gnome-shell[77896]: segfault at 140 ip 00007e53082487f6 sp 00007e52b37eafe0 error 4 in[7e5308228000+188000] likely on CPU 4 (core 8, socket 0)
[86941.402574] Code: 84 ed 74 60 e8 2b fd fd ff 49 8b 1c 24 49 89 c7 48 85 db 75 15 eb 36 0f 1f 44 00 00 49 8b 5c 24 08 49 83 c4 08 48 85 db 74 23 <44> 3a 2b 75 ed 4c 89 fa 48 89 de 4c 89 f7 e8 f7 fd fd ff 85 c0 75

Could you add "drm.debug=0x1e" to /etc/default/grub change the below line
   GRUB_CMDLINE_LINUX="log_buf_len=16M drm.debug=0x1e"
Then run
   sudo update-grub
and reboot to capture the dmesg log again after unplug the HDMI.

Revision history for this message
Anne Chew Yii Huei (annecyh) wrote :

Hi Acelan,

I've updated the grub file and saved the latest dmesg log.
Hope the log contains the info you expect.


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