Bug 497632 - Flaky performance with multiple displays (3+)?
Summary: Flaky performance with multiple displays (3+)?
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: multi-screen (show other bugs)
Version: 6.2.4
Platform: Neon Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: multiscreen
Depends on:
Blocks:
 
Reported: 2024-12-18 00:03 UTC by Jeff Beardsley
Modified: 2025-03-14 23:20 UTC (History)
5 users (show)

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Description Jeff Beardsley 2024-12-18 00:03:53 UTC
SUMMARY

After being "locked" for awhile, upon unlocking, one of my three displays will turn off, after blinking on and off (slowly) for a few seconds. It's usually the right-most display in my case, though it's *sometimes* the middle display.  For a long time I thought it was hardware.  I used to reboot whenever this happened, and cuss while it was booting, ....  

I have discovered though, that it can be restored quite easily (though it still causes some language :).

* Launch Display Configuration (via desktop context menu).
* In the "Drag screens to re-arrange them" area, select the offending display/screen
* Uncheck the "Enabled" checkbox below, and hit "Apply".
* Momentarily a small dialog asks you you if you want to "Keep" or "Restore" the setting.
* Selecting "Restore" (or letting the time run out) will restore the setting, and put it back into a working state.

STEPS TO REPRODUCE
I don't know how to cause this to happen, but I see it every couple days, sometimes more  than once in a day.
I am certain some other developers out there (having 3 or more displays) have seen this issue. 

This may be the same on Wayland, but I've only seen it on X11, because I cannot run Wayland with Eclipse IDE (which I use for work)

SOFTWARE/OS VERSIONS

Operating System: KDE neon 6.2
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.9.0
Qt Version: 6.8.1
Kernel Version: 6.8.0-51-generic (64-bit)
Graphics Platform: X11
Processors: 32 × AMD Ryzen 9 7950X 16-Core Processor
Memory: 46.7 GiB of RAM
Graphics Processor: AMD Radeon RX 6600
Manufacturer: ASUS
Comment 1 Nate Graham 2024-12-18 17:47:09 UTC
Some questions:
1. What's the make and model of the affected screen?
2. Is it always just this screen, even if you move it to a different position in the screen arrangement?
3. Can you try with Wayland anyway to see if the issue reproduces there? I'm not suggesting you use it full-time, just for testing purposes.
3a. What's the problem with Eclipse on Wayland? It should be able to run just fine using XWayland, no?
Comment 2 Jeff Beardsley 2024-12-18 20:15:45 UTC
(In reply to Nate Graham from comment #1)
> Some questions:
> 1. What's the make and model of the affected screen?

The screens are all ViewSonic VA2719-2K monitors (bought the same day because I am a bit OCD, they need to look and act the same :)

> 2. Is it always just this screen, even if you move it to a different position in the screen arrangement?

It's not always the same screen.  Usually it's #3 (the right-most).  About 10% of the time it's #2

> 3. Can you try with Wayland anyway to see if the issue reproduces there? I'm not suggesting you use it full-time, just for testing purposes.
I will try
> 3a. What's the problem with Eclipse on Wayland? It should be able to run just fine using XWayland, no?
I will check out XWayland.  If that fixes my Eclipse problem, I'm happy to run full-time on Wayland.
Comment 3 Jeff Beardsley 2024-12-19 09:55:03 UTC
> 3. Can you try with Wayland anyway to see if the issue reproduces there? 

I got running on Wayland yesterday afternoon, and had no problems the rest of the day, into evening.  After sleeping however, the problem occurred upon unlocking.  Exactly as it does in X11.  In this case display #2 (The middle one) went black immediately.

As above, invoking Display Configuration, disabling the affected display and then restoring brought the display back  on.
Comment 4 Nate Graham 2024-12-19 18:39:25 UTC
Might be an issue with identical displays that's being worked on.