KDE delayed display update / konsole artifacts

Bug #1944951 reported by Horst Schirmeier
24
This bug affects 4 people
Affects Status Importance Assigned to Milestone
mesa (Ubuntu)
Confirmed
Undecided
Unassigned

Bug Description

Since one of the recent Impish updates, konsole shows artifacts and reacts slowly. In fact, it looks like screen updates are pipelined on pixel-group granularity somehow, and the pipeline isn't drained completely: When more text goes to the terminal (e.g., I type something), existing artifacts vanish, but new ones (in the new text) appear.

Unfortunately, I don't see any of the previous konsole .deb releases (e.g. 4:21.08.1-1 or 4:21.08.0-1) on the Ubuntu mirrors, so I cannot go back and simply check whether the newest konsole updates are the culprit. I'm actually not sure whether konsole is responsible at all, I originally intended to file against xorg; however, I see those artifacts in neither xterm nor gnome-terminal.

Find attached a screenshot (taken with an external camera; these artifacts cannot be recorded using a screenshot tool such as imagemagick's "import") where I ran "ls" in /tmp, and cleared the terminal with ^L afterwards. The screen is still littered with remains of the "ls" output. It took a few tries to get artifacts this pronounced, though; usually they only concern small parts of the terminal.

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: xorg 1:7.7+22ubuntu1
ProcVersionSignature: Ubuntu 5.13.0-16.16-generic 5.13.13
Uname: Linux 5.13.0-16-generic x86_64
ApportVersion: 2.20.11-0ubuntu69
Architecture: amd64
CasperMD5CheckResult: unknown
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: KDE
Date: Fri Sep 24 08:09:18 2021
DistUpgraded: 2021-08-08 15:09:23,066 DEBUG Running PostInstallScript: '/usr/lib/ubuntu-advantage/upgrade_lts_contract.py'
DistroCodename: impish
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation HD Graphics 530 [8086:191b] (rev 06) (prog-if 00 [VGA controller])
   Subsystem: Lenovo HD Graphics 530 [17aa:5050]
   Subsystem: Lenovo GM108M [GeForce 940MX] [17aa:5050]
InstallationDate: Installed on 2016-11-26 (1762 days ago)
InstallationMedia: Kubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.1)
MachineType: LENOVO 20FXS05500
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.13.0-16-generic root=/dev/mapper/vgubuntu-root ro kopt=root=/dev/mapper/vgubuntu-root resume=/dev/mapper/vgubuntu-swap nouveau.runpm=0 mitigations=off i915.i915_enable_fbc=0
SourcePackage: xorg
UpgradeStatus: Upgraded to impish on 2021-08-08 (46 days ago)
dmi.bios.date: 10/24/2019
dmi.bios.release: 2.30
dmi.bios.vendor: LENOVO
dmi.bios.version: R07ET90W (2.30 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20FXS05500
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: None
dmi.ec.firmware.release: 1.5
dmi.modalias: dmi:bvnLENOVO:bvrR07ET90W(2.30):bd10/24/2019:br2.30:efr1.5:svnLENOVO:pn20FXS05500:pvrThinkPadT460p:skuLENOVO_MT_20FX_BU_Think_FM_ThinkPadT460p:rvnLENOVO:rn20FXS05500:rvrNotDefined:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad T460p
dmi.product.name: 20FXS05500
dmi.product.sku: LENOVO_MT_20FX_BU_Think_FM_ThinkPad T460p
dmi.product.version: ThinkPad T460p
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.107-1
version.libgl1-mesa-dri: libgl1-mesa-dri 21.2.1-2ubuntu2
version.libgl1-mesa-glx: libgl1-mesa-glx 21.2.1-2ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.20.13-1ubuntu1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.6-2build1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-2
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A

Revision history for this message
Horst Schirmeier (horst) wrote :
Revision history for this message
Horst Schirmeier (horst) wrote :

I went back to konsole 20.04.0 (built from upstream sources) and still see these artifacts. Consequently, something else in the xorg/KDE software stack must be responsible; I'm not sure how to proceed with debugging, though.

Revision history for this message
Horst Schirmeier (horst) wrote (last edit ):

Additional notes:
- Nice reproducer: rsync --progress (the progress output is constantly littered with artifacts)
- Artifacts vanish (temporarily) when I press the ALT key. Other keys do not have this effect.
- Artifacts are much more frequent / likely / pronounced when the system is under load (one core at ~20% CPU running rsync suffices).

Revision history for this message
Horst Schirmeier (horst) wrote :

Update: This isn't a konsole-only issue. I'm seeing this in LibreOffice Writer as well.

Revision history for this message
Horst Schirmeier (horst) wrote :

"Fixed" by completely clearing ~/.config/ .

Revision history for this message
andik (andikies) wrote :

It looks that I'm struck by the same bug. For me all KDE applications show display problems, not only just konsole. But konsole is the one that's used most often.

After you have "fixed" you installation now, could you please turn off the composite manager.
Just use Shift-Alt-F12 for that. I do not get any display errors here as long as the composite manager runs.

Is the problem back without composite manager?

Revision history for this message
Launchpad Janitor (janitor) wrote :

Status changed to 'Confirmed' because the bug affects multiple users.

Changed in xorg (Ubuntu):
status: New → Confirmed
Revision history for this message
Horst Schirmeier (horst) wrote :

Yes! The artifacts reappear when I hit Shift-Alt-F12. Good catch!

summary: - delayed display update / konsole artifacts
+ KDE delayed display update / konsole artifacts
affects: xorg (Ubuntu) → kwin (Ubuntu)
Revision history for this message
andik (andikies) wrote :

Maybe this helps:

I'm using a somewhat newer version of the Intel VGA:

00:02.0 VGA compatible controller: Intel Corporation CometLake-S GT2 [UHD Graphics 630] (rev 03)
and I do not have an additional Nvidia card.

Switching from modesetting_drv.so to intel_drv.so also causes the problem is disappear, but the Intel driver sometimes produces annoying screen flickering.

Revision history for this message
andik (andikies) wrote (last edit ):

Tried a few more things:

Booted from the Kubuntu 21.10 live beta DVD, problem persists.
Booted from KDE Neon DVD, no artefacts.

Turned on composite management, started a new konsole. Turned off composite management.
Konsole display is without errors. So I can have one konsole with problems and another one without at the same time. Nevertheless the "about" dialog shows artefacts.

Manually replaced package xserver-xorg-core with version from 21.04, problem persists after Xorg restart.

Revision history for this message
Michael Weghorn (michaelweghorn) wrote :

I'm having this issue on Debian testing as well, after an upgrade of Mesa packages from 20.3.5-1 to 21.2.4-1.
The problem disappears after downgrading to version 20.3.5-1 of the packages and rebooting (packages in my case: libegl-mesa0 libegl1-mesa-dev libgl1-mesa-dev libgl1-mesa-dri libglapi-mesa libglx-mesa0 mesa-va-drivers mesa-vdpau-drivers mesa-vulkan-drivers libgbm1 libgbm-de).

Testing with versions in between from snapshot.debian.org reveals that it's still OK with 21.1.6-1 and the issue starts with 21.2.0-1.

Other related reports that look like they might be about the same problem, all related to Mesa 21.2 (I'm seeing artifacts in Firefox and in Konsole as described, as well as in other applications):

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=994057
https://forum.manjaro.org/t/konsole-tmux-rendering-problems-horizontal-stripes/86975

Graphics card info from 'hwinfo' output:

    49: PCI 02.0: 0300 VGA compatible controller (VGA)
      [Created at pci.386]
      Unique ID: _Znp.A3c8F1k8IIB
      SysFS ID: /devices/pci0000:00/0000:00:02.0
      SysFS BusID: 0000:00:02.0
      Hardware Class: graphics card
      Device Name: "Onboard IGD"
      Model: "Intel UHD Graphics 630 (Mobile)"
      Vendor: pci 0x8086 "Intel Corporation"
      Device: pci 0x3e9b "UHD Graphics 630 (Mobile)"
      SubVendor: pci 0x103c "Hewlett-Packard Company"
      SubDevice: pci 0x8610
      Revision: 0x02
      Driver: "i915"
      Driver Modules: "i915"
      Memory Range: 0xe4000000-0xe4ffffff (rw,non-prefetchable)
      Memory Range: 0xa0000000-0xafffffff (ro,non-prefetchable)
      I/O Ports: 0x4000-0x403f (rw)
      Memory Range: 0x000c0000-0x000dffff (rw,non-prefetchable,disabled)
      IRQ: 166 (44948 events)
      Module Alias: "pci:v00008086d00003E9Bsv0000103Csd00008610bc03sc00i00"
      Driver Info #0:
        Driver Status: i915 is active
        Driver Activation Cmd: "modprobe i915"
      Config Status: cfg=new, avail=yes, need=no, active=unknown

Revision history for this message
andik (andikies) wrote :

Thanks to the tests done by Michael it was easy to figure out the file in question.
It's the file iris_dri.so from package libgl1-mesa-dri.
Taken it from 21.0.3 and it worked.
Don't know if it's safer just to replace this file or all Mesa libraries.

Revision history for this message
Michael Weghorn (michaelweghorn) wrote :

[1] says that the issue will be fixed in Mesa 21.3.0.

[1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=994057#44

Revision history for this message
andik (andikies) wrote :

Package libgl1-mesa-dri, file iris_dri.so

affects: kwin (Ubuntu) → mesa (Ubuntu)
Revision history for this message
andik (andikies) wrote :

Verified libgl1-mesa-dri_21.3.0~rc5-1_amd64.deb from Debian, it works.

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