Video framebuffer loopback (intermittent)

[antonioprates]

The issue, I observe mostly when I am typing some text in the browser (brave) or in the terminal (terminator), or in IDE (intellij or code-oss). What happens is that video frames seem to roll back in time and forth again. Like it goes back for what was on my screen like one second ago, and then returns to the current updated state. It fixes itself, always, but this hiccup is quite annoying. And it’s enough frequent that I decided I should take action and try to find a solution.

I couldn’t find much more about how to debug video / framebuffer issues on Google, except for some very outdated stuff (from a decade ago) and not specific to Manjaro. So any help is welcome, like where should I start looking? Is this a known issue?

Note: this error happens quite a few times through a workday, but usually not so frequently like every minute. Although it can happen more then once in a minute, but sometimes takes hours to replicate. But it seems application agnostic as well as load agnostic. And it has been there for a while now sometimes, I even believe it has been there since day1 (8 months ago), but I have not observed this behaviour on Windows (although I use win way less often than Manjaro)

Some basic info about my laptop:
OS: Manjaro Linux x86_64
Host: CoreBook X
Kernel: 5.10.70-1-MANJARO
Uptime: 7 hours, 2 mins
Packages: 1423 (pacman)
Shell: zsh 5.8
Resolution: 2160x1440
DE: Xfce 4.16
WM: Xfwm4
WM Theme: Kali-Dark-HiDPI
Theme: Kali-Dark [GTK2/3]
Icons: ePapirus-Dark [GTK2/3]
Terminal: terminator
CPU: Intel i5-7267U (4) @ 3.500GHz
GPU: Intel Iris Plus Graphics 650
Memory: 2886MiB / 15918MiB

[antonioprates]

I was able to capture it by recording my screen using my phone (I tried with a screen capture software but it didn’t manage to capture the issue). Now with this video, it seem I managed to reproduce it more consistently… In this case it’s happening when I click on a different line on IntelliJ, then just move the mouse around and you can see the framebuffer jumping back and forth until it settles on the final state. But as I said it’s not exclusive to one application, in fact, I notice it more frequently when typing on terminal: Dropbox - video_2021-10-14_17-06-57.mp4 - Simplify your life

[antonioprates]

After I posted the video I read somewhere that Linux kernels could affect video output, so I downgraded from 5.10.70-1-MANJARO to 5.4.150-1-MANJARO and it seems to solve the issue - Since then I couldn’t observe the video failure happening again. I guess this problem was related to my old hardware in combination to the more recent kernel I was running before…