[i915] ‘no signal’ after monitor sleep or monitor turned off

[Havard Bjastad]

The problem and a workaround is well described here: https://forums.developer.nvidia.com/t/ubuntu-20-04-no-signal-after-monitor-sleep-or-monitor-turned-off/180056

My laptop is connected to an external monitor (Dell) via HDMI. When the laptop is left idle for some time, the screen goes black and the monitor reports "no signal". When I press a keyboard button or move the mouse, the laptop screen comes on...but the monitor still receives no signal.

Workaround 1 is to unplug and replug the HDMI cable.
Workaround 2 is to press ctrl-alt-F3 to get into a text-based console, and then ctrl-alt-F1 or F2 to get back to graphical mode

My laptop has Intel GPU, not Nvidia, so this seems to be a problem with Ubuntu.
I'm currently running Ubuntu 24.04 LTS

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: xorg 1:7.7+23ubuntu3
ProcVersionSignature: Ubuntu 6.8.0-31.31-generic 6.8.1
Uname: Linux 6.8.0-31-generic x86_64
ApportVersion: 2.28.1-0ubuntu2
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: pass
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Sat May 25 12:23:02 2024
DistUpgraded: Fresh install
DistroCodename: noble
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Meteor Lake-P [Intel Graphics] [8086:7d45] (rev 08) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Meteor Lake-P [Intel Graphics] [17aa:231e]
InstallationDate: Installed on 2024-04-30 (25 days ago)
InstallationMedia: Ubuntu 24.04 LTS "Noble Numbat" - Release amd64 (20240424)
MachineType: LENOVO 21KCCTO1WW
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-6.8.0-31-generic root=UUID=c613759c-7da4-4d83-afb2-c8423d857ed1 ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/02/2024
dmi.bios.release: 1.27
dmi.bios.vendor: LENOVO
dmi.bios.version: N3YET62W (1.27 )
dmi.board.asset.tag: Not Available
dmi.board.name: 21KCCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0T76461 WIN
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.21
dmi.modalias: dmi:bvnLENOVO:bvrN3YET62W(1.27):bd04/02/2024:br1.27:efr1.21:svnLENOVO:pn21KCCTO1WW:pvrThinkPadX1CarbonGen12:rvnLENOVO:rn21KCCTO1WW:rvrSDK0T76461WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_21KC_BU_Think_FM_ThinkPadX1CarbonGen12:
dmi.product.family: ThinkPad X1 Carbon Gen 12
dmi.product.name: 21KCCTO1WW
dmi.product.sku: LENOVO_MT_21KC_BU_Think_FM_ThinkPad X1 Carbon Gen 12
dmi.product.version: ThinkPad X1 Carbon Gen 12
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.120-2build1
version.libgl1-mesa-dri: libgl1-mesa-dri 24.0.5-1ubuntu1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:21.1.12-1ubuntu1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:22.0.0-1build1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20210115-1build1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-2build1

[Sasha (sir-enmity)]

I have the same problem: whenever my laptop sleeps two external monitors flicker/blink for a while and then show "no signal" message. Only one solution that sometimes helps is to open laptop lid or disconnect/connect monitors.

[Daniel van Vugt (vanvugt)]

Please try setting the external monitor to a lower resolution like 1920x1080. If the bug then stops happening it would suggest a higher quality display cable is needed.

[Daniel van Vugt (vanvugt)]

Please also provide a log from as soon as the bug occurs:

  journalctl -b0 > journal.txt

[Havard Bjastad (havard-bjastad)]

Attached is the journal file from around the time when it happened

[Havard Bjastad (havard-bjastad)]

I have also tried your other suggestion, lowering the resolution to 1920x1080, and you're right - then the problem is gone. So I'll try with a different display cable (I'm now using the one that came with the monitor).

[Daniel van Vugt (vanvugt)]

Sounds similar to bug 2066129 and bug 2066307, but currently we're blaming those on the Nvidia driver. And you seem to be using Intel graphics.

[Havard Bjastad (havard-bjastad)]

Yes, I'm using Intel graphics, there's no Nvidia in this laptop

[Daniel van Vugt (vanvugt)]

This log message might be related:

May 29 23:01:32 havard-X1-G12 gnome-shell[2394]: Cursor update failed: drmModeAtomicCommit: Invalid argument

If you repeat the bug a few times, does that message or something similar occur on wakeup? (journalctl -b0)

[Sasha (sir-enmity)]

It is super annoying. Usually it starts happening after waking up. One thing that sometimes helps is the replugging of the docker/monitors or opening the laptop lid.
I have never had such a problem on ubuntu 22.04
Please find the logs attached. If I can help to debug by providing any extra logs - please let me know.