Apps interface flickering

[Diego Garcia]

It has been 1-ish months since this problem appeared.
The app/system interface randomly starts flickering. This problem doesn't occur on the entire system, sometime it occurs in some apps, other times in the system, and other times all of these.
It occurs since installation.

Some images and videos (Unfortunetly you'll need to download the videos)
https://media.discordapp.net/attachments/748527796405403749/836001618255806484/unknown.png
https://media.discordapp.net/attachments/748527796405403749/836004993991311400/unknown.png
https://media.discordapp.net/attachments/586951783944028179/832728657075372102/unknown.png
https://cdn.discordapp.com/attachments/804416273701797909/832780706790375444/20210416_215049_576x324.mp4
https://cdn.discordapp.com/attachments/748527796405403749/836048880592355368/simplescreenrecorder-2021-04-25_22.05.52.mp4

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.8.0-50.56~20.04.1-generic 5.8.18
Uname: Linux 5.8.0-50-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
BootLog: Error: [Errno 13] Permissão negada: '/var/log/boot.log'
CasperMD5CheckResult: skip
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Sun Apr 25 22:23:48 2021
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
DkmsStatus: v4l2loopback, 0.12.3, 5.8.0-50-generic, x86_64: installed
ExtraDebuggingInterest: Yes, including running git bisection searches
GraphicsCard:
 Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer 3rd Gen Core processor Graphics Controller [1297:2027]
InstallationDate: Installed on 2021-04-17 (9 days ago)
InstallationMedia: Ubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
MachineType: Positivo Informatica SA DC8CR01TV
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.8.0-50-generic root=UUID=e2946f04-ffa3-4934-b119-e6dcc363a2da ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/31/2014
dmi.bios.release: 4.6
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 2.01.U
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: DC8CR01TV
dmi.board.vendor: Positivo Informatica SA
dmi.board.version: POSITIVO
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 13
dmi.chassis.vendor: Positivo Informatica SA
dmi.chassis.version: POSITIVO
dmi.ec.firmware.release: 1.22
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2.01.U:bd03/31/2014:br4.6:efr1.22:svnPositivoInformaticaSA:pnDC8CR01TV:pvr2.01.U_POS_TV:rvnPositivoInformaticaSA:rnDC8CR01TV:rvrPOSITIVO:cvnPositivoInformaticaSA:ct13:cvrPOSITIVO:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: DC8CR01TV
dmi.product.sku: 1700644
dmi.product.version: 2.01.U_POS_TV
dmi.sys.vendor: Positivo Informatica SA
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.102-1ubuntu1~20.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 20.2.6-0ubuntu0.20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.9-2ubuntu1.2~20.04.2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1

[Sebastien Bacher (seb128)]

Thank you for your bug report, do you remember what packages got updated at the time the issue started (the /var/log/dpkg.log record could help figuring it out)? Could you try if starting an older kernel (https://askubuntu.com/questions/82140/how-can-i-boot-with-an-older-kernel-version) makes a difference? What videocard, driver and desktop environment do you use?

[Md Ayquassar (mdayquassar)]

Same flickering effect for me on groovy. I don't know which packages got updates back then. As for now, I run 5.8.0-50 and don't have older kernels. The videocard is this:

00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06) (prog-if 00 [VGA controller])
        DeviceName: Onboard IGD
        Subsystem: Dell 4th Gen Core Processor Integrated Graphics Controller
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0
        Interrupt: pin A routed to IRQ 39
        Region 0: Memory at f5800000 (64-bit, non-prefetchable) [size=4M]
        Region 2: Memory at d0000000 (64-bit, prefetchable) [size=256M]
        Region 4: I/O ports at f000 [size=64]
        Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
        Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
                Address: fee00018 Data: 0000
        Capabilities: [d0] Power Management version 2
                Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
                Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [a4] PCI Advanced Features
                AFCap: TP+ FLR+
                AFCtrl: FLR-
                AFStatus: TP-
        Kernel driver in use: i915
        Kernel modules: i915

I run xorg+gdm3. I don't know why wayland fails to start.

[Diego Garcia (d1360-64rc14)]

I run Ubuntu 20.04.2 LTS GNOME (Xorg)
Processor Intel Core i3-3110M (HD Graphics 4000)
I'll install an older kernel version (5.0) and test it in the next day at 1PM (my actual version is 5.8.0-50-generic)
I have already formated my linux, so I don't have the dpkg.log

Here is my lspci:
------------------------------------------------
00:02.0 VGA compatible controller: Intel Corporation 3rd Gen Core processor Graphics Controller (rev 09) (prog-if 00 [VGA controller])
 DeviceName: Onboard IGD
 Subsystem: Holco Enterprise Co, Ltd/Shuttle Computer 3rd Gen Core processor Graphics Controller
 Flags: bus master, fast devsel, latency 0, IRQ 33
 Memory at f3400000 (64-bit, non-prefetchable) [size=4M]
 Memory at d0000000 (64-bit, prefetchable) [size=256M]
 I/O ports at f000 [size=64]
 Expansion ROM at 000c0000 [virtual] [disabled] [size=128K]
 Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
 Capabilities: [d0] Power Management version 2
 Capabilities: [a4] PCI Advanced Features
 Kernel driver in use: i915
 Kernel modules: i915
------------------------------------------------

[Diego Garcia (d1360-64rc14)]

Update: so far, the system has not shown any irregularities. I'll wait for 3 days because this problem does not have a pattern. It seems to happen when the system is under high load, but I'm not sure.

[Md Ayquassar (mdayquassar)]

After switching from X on groove to wayland on hirsute, I see no flickering.

[Diego Garcia (d1360-64rc14)]

Update: no flickering in this time period.

Downgrading to an older kernel version (5.0.0-050000-generic) solved the problem.
Aparently the kernel version 5.8.0-50-generic has some problem between Intel Graphics and Xorg.

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1924624, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.