dmesg output with GPU HANGs, below.
While running, it's fairly easy to cause flashing of text within a window, flipping between one window and another (eg. two tabs in gnome-terminal), or even complete freeze-ups, by moving a window or switching between windows, a little too quickly.
This is a basically new install of Ubuntu 20.04 on a ThinkPad W530 running Intel graphics and with kernel 5.8.0-50-generic.
----------
$ dmesg -T | grep -i i915
[Mon Apr 19 22:01:39 2021] i915 0000:00:02.0: vgaarb: deactivate vga console
[Mon Apr 19 22:01:39 2021] i915 0000:00:02.0: vgaarb: changed VGA decodes: olddecodes=io+mem,decodes=io+mem:owns=io+mem
[Mon Apr 19 22:01:39 2021] [drm] Initialized i915 1.6.0 20200515 for 0000:00:02.0 on minor 0
[Mon Apr 19 22:01:39 2021] fbcon: i915drmfb (fb0) is primary device
[Mon Apr 19 22:01:40 2021] i915 0000:00:02.0: fb0: i915drmfb frame buffer device
[Mon Apr 19 22:02:12 2021] snd_hda_intel 0000:00:1b.0: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
[Mon Apr 19 22:02:24 2021] i915 0000:00:02.0: [drm] GPU HANG: ecode 7:0:00000000
[Mon Apr 19 22:02:24 2021] i915 0000:00:02.0: [drm] Resetting chip for stopped heartbeat on rcs0
[Mon Apr 19 22:02:24 2021] i915 0000:00:02.0: [drm] gnome-shell[3417] context reset due to GPU hang
[Mon Apr 19 22:02:27 2021] i915 0000:00:02.0: [drm] GPU HANG: ecode 7:1:ccddeeff, in gnome-shell [3417]
[Mon Apr 19 22:02:27 2021] i915 0000:00:02.0: [drm] Resetting chip for stopped heartbeat on rcs0
[Mon Apr 19 22:02:39 2021] i915 0000:00:02.0: [drm] GPU HANG: ecode 7:1:ccddeeff
[Mon Apr 19 22:02:39 2021] i915 0000:00:02.0: [drm] Resetting chip for stopped heartbeat on rcs0
[Mon Apr 19 22:05:17 2021] i915 0000:00:02.0: [drm] GPU HANG: ecode 7:1:003f003f, in Renderer [11805]
[Mon Apr 19 22:05:17 2021] i915 0000:00:02.0: [drm] Resetting chip for stopped heartbeat on rcs0
[Mon Apr 19 22:05:17 2021] i915 0000:00:02.0: [drm] Renderer[11805] context reset due to GPU hang
[Mon Apr 19 22:05:28 2021] i915 0000:00:02.0: [drm] GPU HANG: ecode 7:1:40d84443, in Renderer [11805]
[Mon Apr 19 22:05:28 2021] i915 0000:00:02.0: [drm] Resetting chip for stopped heartbeat on rcs0
[Mon Apr 19 22:05:28 2021] i915 0000:00:02.0: [drm] Renderer[11805] context reset due to GPU han
---
ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: dev 4268 F.... pulseaudio
CasperMD5CheckResult: skip
DistroRelease: Ubuntu 20.04
InstallationDate: Installed on 2021-02-05 (74 days ago)
InstallationMedia: Ubuntu 20.04.2 LTS "Focal Fossa" - Release amd64 (20210204)
MachineType: LENOVO 2436CTO
Package: linux (not installed)
ProcEnviron:
TERM=xterm-256color
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.8.0-50-generic root=UUID=5d036090-3f9e-4adf-a198-e0db3da45582 ro rootflags=subvol=@ luks.crypttab=no quiet
ProcVersionSignature: Ubuntu 5.8.0-50.56~20.04.1-generic 5.8.18
PulseList: Error: command ['pacmd', 'list'] failed with exit code 1: No PulseAudio daemon running, or not running as session daemon.
RelatedPackageVersions:
linux-restricted-modules-5.8.0-50-generic N/A
linux-backports-modules-5.8.0-50-generic N/A
linux-firmware 1.187.10
RfKill:
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: yes
Tags: focal
Uname: Linux 5.8.0-50-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: N/A
_MarkForUpload: True
dmi.bios.date: 06/11/2018
dmi.bios.release: 2.72
dmi.bios.vendor: LENOVO
dmi.bios.version: G5ETB2WW (2.72 )
dmi.board.asset.tag: Not Available
dmi.board.name: 2436CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.ec.firmware.release: 1.13
dmi.modalias: dmi:bvnLENOVO:bvrG5ETB2WW(2.72):bd06/11/2018:br2.72:efr1.13:svnLENOVO:pn2436CTO:pvrThinkPadW530:rvnLENOVO:rn2436CTO:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.family: ThinkPad W530
dmi.product.name: 2436CTO
dmi.product.sku: LENOVO_MT_2436
dmi.product.version: ThinkPad W530
dmi.sys.vendor: LENOVO
apport information