RE: Flickering problems on external monitor with HDMI after installing Ubuntu 23.10

[J K]

this is a continuation of the bug reported in https://bugs.launchpad.net/ubuntu/+bug/2062504

I reinstalled ubuntu 23, and didn't install anything else. I'm still having the flickering when connecting an HDMI to an external monitor. please help

ProblemType: Bug
DistroRelease: Ubuntu 23.10
Package: xorg 1:7.7+23ubuntu2
ProcVersionSignature: Ubuntu 6.5.0-28.29-generic 6.5.13
Uname: Linux 6.5.0-28-generic x86_64
ApportVersion: 2.27.0-0ubuntu5
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: pass
CloudArchitecture: x86_64
CloudID: none
CloudName: none
CloudPlatform: none
CloudSubPlatform: config
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Fri Apr 19 22:27:21 2024
DistUpgraded: Fresh install
DistroCodename: mantic
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation Alder Lake-UP3 GT2 [Iris Xe Graphics] [8086:46a8] (rev 0c) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Alder Lake-UP3 GT2 [Iris Xe Graphics] [17aa:50a6]
InstallationDate: Installed on 2024-04-20 (0 days ago)
InstallationMedia: Ubuntu 23.10.1 "Mantic Minotaur" - Release amd64 (20231016.1)
MachineType: {report['dmi.sys.vendor']} {report['dmi.product.name']}
ProcEnviron:
 LANG=en_US.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=xterm-256color
 XDG_RUNTIME_DIR=<set>
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.5.0-28-generic root=UUID=92611de2-ed0a-4611-b724-820a5d29be02 ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/23/2024
dmi.bios.release: 1.23
dmi.bios.vendor: LENOVO
dmi.bios.version: R1UET46W (1.23 )
dmi.board.asset.tag: Not Available
dmi.board.name: 21B4S4QB00
dmi.board.vendor: LENOVO
dmi.board.version: SDK0T76465 WIN
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.14
dmi.modalias: dmi:bvnLENOVO:bvrR1UET46W(1.23):bd02/23/2024:br1.23:efr1.14:svnLENOVO:pn21B4S4QB00:pvrThinkPadL13Gen3:rvnLENOVO:rn21B4S4QB00:rvrSDK0T76465WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_21B4_BU_Think_FM_ThinkPadL13Gen3:
dmi.product.family: ThinkPad L13 Gen 3
dmi.product.name: 21B4S4QB00
dmi.product.sku: LENOVO_MT_21B4_BU_Think_FM_ThinkPad L13 Gen 3
dmi.product.version: ThinkPad L13 Gen 3
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.115-1
version.libgl1-mesa-dri: libgl1-mesa-dri 23.2.1-1ubuntu3
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:21.1.7-3ubuntu2.9
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-3
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20210115-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-2build1

[Daniel van Vugt (vanvugt)]

Thanks for the bug report. Most likely the problem is an HDMI connection problem. Please try a new HDMI cable if you can. If you can't then please try temporarily running the external monitor at a lower resolution to see if the flicker then goes away.

If the flicker still persists then please attach a video of the issue (recording on a phone is fine).

[J K (cypherscouter)]

I had the same problem when using another HDMI cable

I couldn't change the external monitor to a lower resolution because it kept flickering and going to the menu for the external monitor, it would just reset and send me to the settings for the built-in monitor

I attached a video

[Daniel van Vugt (vanvugt)]

Thanks. It was unclear from the first bug which monitor was flickering. In the first bug it sounded like the laptop. In this second bug it sounded like the external monitor. Now the video shows it's the laptop screen.

Is it only the laptop screen flickering?

I'm wondering if this is due to a loss of HDMI connection to the external monitor causing the system to reconfigure all displays including the built-in.

Next time the problem happens, please open a Terminal and run:

  journalctl -b0 > journal.txt

and attach the resulting file here.

[J K (cypherscouter)]

yes, its the laptop screen that flickers. It only flickers when I plug in the HDMI cable. The external monitor shows nothing when I plug in the HDMI cable

I attached the file

[Daniel van Vugt (vanvugt)]

Thanks. I don't see any errors relevant to this bug, only bug 2034664 (which you should have the fix for already?) and bug 1857392.

Next please try deleting the monitor layout settings:

  rm ~/.config/monitors.xml

and then log in again. Does that improve the situation?

[J K (cypherscouter)]

I don't know if I have the fix for bug 2034664

I can't delete that monitors.xml since it doesn't exist in my computer in that directory

[Daniel van Vugt (vanvugt)]

Not having a monitors.xml is fine. I was only concerned about the possibility of monitors.xml containing bad data.

What if you choose 'Ubuntu on Xorg' on the login screen (menu in the bottom right corner). Does that prevent the bug from occurring?

[J K (cypherscouter)]

If I choose Xorg then I still get that bug

[Daniel van Vugt (vanvugt)]

Please try adding this to /etc/environment:

  MUTTER_DEBUG_FORCE_KMS_MODE=simple

and reboot.

[J K (cypherscouter)]

I tried and that the issue is still the same as before