Bug 24060 - Qt 5.12 & Plasma 5.14.4 & KF 5.53 update causes Plasma desktop screen to flicker when OpenGL compositing background is used (when using intel or nouveau video drivers)
Summary: Qt 5.12 & Plasma 5.14.4 & KF 5.53 update causes Plasma desktop screen to flic...
Status: NEW
Alias: None
Product: Mageia
Classification: Unclassified
Component: RPM Packages (show other bugs)
Version: Cauldron
Hardware: x86_64 Linux
Priority: release_blocker critical
Target Milestone: ---
Assignee: KDE maintainers
QA Contact:
URL:
Whiteboard:
Keywords: 7beta1, 7beta2
Depends on:
Blocks:
 
Reported: 2018-12-25 20:45 CET by Jüri Ivask
Modified: 2019-01-14 10:11 CET (History)
12 users (show)

See Also:
Source RPM:
CVE:
Status comment:


Attachments
screenshot of a Plasma system settings compositor page (73.06 KB, image/png)
2019-01-06 19:57 CET, Thomas Andrews
Details

Description Jüri Ivask 2018-12-25 20:45:07 CET
Description of problem:Qt 5.12 & Plasma 5.14.4 & KF 5.53 update causes Plasma desktop screen to flicker and impossible to use


Version-Release number of selected component (if applicable): 5.14.4


Steps to Reproduce:
1. Upgrade to Qt 5.12 & Plasma 5.14.4 & KF 5.53 & all other packages to latest
2. Restart Plasma Desktop
3. Desktop flickers and is impossible to use

Workaround is to edit /.config/kwinrc fail and in the [Compositing] section replace Backend=OpenGL with Backend=XRender

Device: Intel Corporation Skylake GT2 [HD Graphics 520] (Thinkpad X260)
Driver: intel
Comment 1 Jüri Ivask 2018-12-25 21:33:02 CET
Another workaround is to leave compositing backend to OpenGL but replace intel driver with modesetting.
Marja Van Waes 2018-12-26 12:04:33 CET

CC: (none) => kernel, marja11
Summary: Qt 5.12 & Plasma 5.14.4 & KF 5.53 update causes Plasma desktop screen to flicker when OpenGL compositing background is used => Qt 5.12 & Plasma 5.14.4 & KF 5.53 update causes Plasma desktop screen to flicker when OpenGL compositing background is used (on Skylake)
Assignee: bugsquad => kde

Ulrich Beckmann 2018-12-26 21:03:52 CET

See Also: (none) => https://bugs.mageia.org/show_bug.cgi?id=24070

Comment 2 Béat E 2018-12-26 21:06:02 CET
I had the same problem (bug 24070). The first workaround helped. In /.config/kwin I replaced "OpenGLIsUnsafe=false" by "Backend=XRender"

CC: (none) => ed1

Ulrich Beckmann 2018-12-27 15:33:29 CET

CC: (none) => bequimao.de

Comment 3 Martin Whitaker 2018-12-28 20:36:29 CET
For me, on two different machines exhibiting this bug, just changing "OpenGLIsUnsafe=false" to "OpenGLIsUnsafe=true" in ~/.config/kwinrc fixed it.

Machine 1 has Intel Core i7-3630QM CPU with hybrid Intel/NVIDIA graphics (bug seen when using Intel graphics, i915 kernel driver).

Machine 2 has Intel Atom 23735F CPU.

CC: (none) => mageia

JanKusanagi 2018-12-29 01:20:19 CET

CC: (none) => jan-bugs

Martin Whitaker 2019-01-06 10:38:33 CET

Priority: Normal => release_blocker
Severity: normal => critical
Summary: Qt 5.12 & Plasma 5.14.4 & KF 5.53 update causes Plasma desktop screen to flicker when OpenGL compositing background is used (on Skylake) => Qt 5.12 & Plasma 5.14.4 & KF 5.53 update causes Plasma desktop screen to flicker when OpenGL compositing background is used (when using intel or nouveau video drivers)

William Kenney 2019-01-06 15:22:18 CET

CC: (none) => wilcal.int

William Kenney 2019-01-06 15:24:42 CET

Keywords: (none) => 7beta1

Thomas Andrews 2019-01-06 16:18:45 CET

CC: (none) => andrewsfarm

Thomas Andrews 2019-01-06 17:09:35 CET

Keywords: (none) => 7beta2

Comment 4 André DESMOTTES 2019-01-06 17:33:27 CET
same bug here, there wasn't Backend=OpenGL in /.config/kwinrc but I added Backend=XRender anyway. It worked.
I deleted Backend=XRender and changed "OpenGLIsUnsafe=false" to "OpenGLIsUnsafe=true", it worked as well. In both case, system was very slow, about 1 mn between connexion screen and the desktop.

Keywords: 7beta2 => (none)
CC: (none) => lebarhon

Comment 5 Thomas Andrews 2019-01-06 19:56:04 CET
OK, this may get a bit complicated. I'll try to explain what happened, and what I have found. Bear with me, please.

This is all on real hardware, with an Athlon X2 processor, 8GB of RAM, Geforce 9800 GT (nvidia340 driver), and an Atheros-based wifi card. Any installs done are "semi-clean," meaning I format the / partition but leave /home alone. The user I create during the install is the same one I was using on the install it replaced.

A few days ago, I did a Plasma install from the beta 1 Live iso, using the "free" driver (nouveau). After getting over 1,000 pending updates, it was affected by the bug. I made the system usable by changing OpenGLIsUnsafe to "true."

I tried the round 1 beta 2 Live iso earlier today, booting into Live mode with and without the nonfree drivers. free was affected, nonfree was not. I did not do an install from that iso.

I then used the round 1 beta 2 CI iso to install a "standard" Plasma, telling it along the way that I didn't want the proprietary driver.

(Probably unrelated, but I mention this just-in-case) It appears that the nvidia340 driver module was built and installed during the first boot, even though I said I didn't want it. However, indications afterward are that it is not being used.

The resulting system is not affected by the bug. I am using it now. OpenGLIsUnsafe is still "true." One significant change occurs when I look at systemsettings5/Display and Monitor/Compositor. It looks different, almost identical to the same screen in Mageia 6 when the i915 driver is used. (I'll attach a screenshot after I finish this comment.) There is a notice/message at the top about OpenGL crashing kwin in the past, with a button to turn something off if you believe you are now using a "stable" video driver. When using the proprietary nvidia in M6 this notice does NOT appear, and it never did appear after updating the beta1 install.

This notice did NOT suddenly appear when I originally changed OpenGLIsUnsafe, either. It only appeared after I installed a new Plasma/kwin while that change was in effect in my user's .config/kwinrc.

I don't know what can be done with this information, but I would ask... Why can't we do something with Mageia 7 Plasma kwinrc settings during the install process that's similar to what was done with Mageia 6.1 installs?

Keywords: (none) => 7beta2

Comment 6 Thomas Andrews 2019-01-06 19:57:58 CET
Created attachment 10656 [details]
screenshot of a Plasma system settings compositor page
Comment 7 Thomas Andrews 2019-01-07 15:55:37 CET
And of course it's never as simple as "everything using a certain driver."

I just did some checking with my old Dell Dimension E310, vintage around 2004. Details on the hardware can be found at https://wiki.mageia.org/en/QA_iso_hardware_list. It uses the i915 video driver.

This aging hardware is happily using 64-bit Mageia 6 Plasma, updated over time from a Mageia 6 CI install. It is as stable as a rock. Looking at kwinrc, OpenGLIsUnsafe is set to "false."

This is my brother's production computer, so I don't want to do anything that might break his current system, like install Cauldron in its present state on the hard drive. However, I did just boot the Round 2 Plasma Live iso into live mode from a usb stick. Unlike my trials on other Intel systems, it is rock-solid stable. And OpenGLIsUnsafe=false in the live mode kwinrc.

So it looks like the age of the Intel graphics hardware is also an important factor.
Comment 8 Martin Whitaker 2019-01-12 16:38:21 CET
Following on from a discussion on qa-discuss, I have:

1. Installed a minimal Plasma system from the beta1 64-bit CI ISO.
2. Updated everything except the qt5/kf5/Plasma stack from my beta2 repo snapshot.
3. Updated the qt5/kf5/Plasma stack from my beta2 repo snapshot.

After step 2, everything still worked fine. After step3, the display corruption was present. So I think we can rule out a regression in Mesa or the video drivers.

Over to the KDE maintainers...
Comment 9 Thomas Backlund 2019-01-12 16:47:31 CET
I see  qt 5.12.1 and plasma 5.14.5 is being prepared upstream... hopefully they will improve the situation

CC: (none) => tmb

Comment 10 ben mcmonagle 2019-01-13 01:19:50 CET
also affects nvidia Geforce 8100.

install beta2 plasma5 live and rebooted without issue to a working desktop.
add "virtualbox" via Mageia Welcome an d reboot for new kernel

rebooted again during the reboot after dkms installed virtual box driver?

bootedinto an unusable desktop!

changing .config/kwinrc

[Compositing]
OpenGLIsUnsafe=false

to

[Compositing]
OpenGLIsUnsafe=true

corrects the issue for me

CC: (none) => westel

Comment 11 Nicolas Lécureuil 2019-01-14 00:33:17 CET
(In reply to Thomas Backlund from comment #9)
> I see  qt 5.12.1 and plasma 5.14.5 is being prepared upstream... hopefully
> they will improve the situation

i will prepare them on our svn.

CC: (none) => mageia

Comment 12 Nicolas Lécureuil 2019-01-14 00:38:31 CET
i am uploading plasma 5.14.5 in the svn.
I don't see any qt 5.12.1 yet available.
Comment 13 Thomas Backlund 2019-01-14 08:53:18 CET
(In reply to Nicolas Lécureuil from comment #12)

> I don't see any qt 5.12.1 yet available.

Yeah, I dont know what the exact plan for that is... I saw version bumps in qt git, and some already starting to work on 5.12.2:
https://github.com/qt/qtbase/commit/6178913a234dfbb5a24c9128f6460f070fb7ce14

QT release schedule only states "January 2019" for 5.12.1:
https://wiki.qt.io/Qt_5.12_Release
Comment 14 Jüri Ivask 2019-01-14 10:11:38 CET
KDE Frameworks 5.54.0 is available.

But just a question - as for example KDE Neon switched to using modesetting driver as a default one for intel graphics hardware already in November 2016 (https://phabricator.kde.org/T3734), then isn't it time for that change in Mageia too?

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