Lenovo T480 freezes after screen has been locked

[Jussi Lind]

This has now happened multiple times. When I just lock my screen (I have one external monitor attached to my laptop via HDMI) and leave my laptop alone for a while, it has somehow frozen when I get back. I'm not sure how long it will take, but something like 30-60 mins perhaps. Either one or usually both screens are just black and the machine doesn't respond to mouse or anything (haven't tried to SSH to the laptop).

If I just suspend the laptop everything always goes just fine and it always wakes up.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-42-generic 4.15.0-42.45
ProcVersionSignature: Ubuntu 4.15.0-42.45-generic 4.15.18
Uname: Linux 4.15.0-42-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/pcmC0D0p: jussili 2985 F...m pulseaudio
 /dev/snd/controlC0: jussili 2985 F.... pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Fri Mar 1 13:23:13 2019
HibernationDevice: RESUME=UUID=16017bed-4ef5-46e8-9621-733ee431d47d
InstallationDate: Installed on 2018-04-17 (317 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Alpha amd64 (20180416)
MachineType: LENOVO 20L50000MX
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-42-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-42-generic N/A
 linux-backports-modules-4.15.0-42-generic N/A
 linux-firmware 1.173.2
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/12/2018
dmi.bios.vendor: LENOVO
dmi.bios.version: N24ET35W (1.10 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20L50000MX
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40697 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN24ET35W(1.10):bd02/12/2018:svnLENOVO:pn20L50000MX:pvrThinkPadT480:rvnLENOVO:rn20L50000MX:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad T480
dmi.product.name: 20L50000MX
dmi.product.version: ThinkPad T480
dmi.sys.vendor: LENOVO

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

This change was made by a bot.

[Jussi Lind (jussi-lind)]

I attached my kern.log. Today (Mar 1 2019) this issue occurred sometime between 12:00 and 13:00.

I can see things like these, but don't know if they are related:

Mar 1 12:29:25 T480 kernel: [50812.073470] WARNING: CPU: 0 PID: 2861 at /build/linux-Y38gIP/linux-4.15.0/drivers/gpu/drm/drm_vblank.c:1073 drm_wait_one_vblank+0x181/0x190 [drm]

Mar 1 12:29:25 T480 kernel: [50812.073537] CPU: 0 PID: 2861 Comm: Xorg Tainted: G W O 4.15.0-42-generic #45-Ubuntu

[AaronMa (mapengyu)]

Hi Jussi:

It looks like a dc stat issue.
Could you try 4.16 kernel?
https://kernel.ubuntu.com/~kernel-ppa/mainline/v4.16/

If it confirms fixed, I will recompile a kernel for you.

[Jussi Lind (jussi-lind)]

Ok, I'm running 4.16 now. Let's what happens..

[Jussi Lind (jussi-lind)]

Didn't freeze overnight, so maybe 4.16 fixed the issue.