Bug 502151

Summary:	Dual display suspend timeout problem and blackscreen while playing games
Product:	[Plasma] kwin	Reporter:	v_jos <v_josimov>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	nate, plasma-bugs-null
Priority:	NOR	Keywords:	multiscreen, wayland-only
Version First Reported In:	6.3.3
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description v_jos 2025-03-29 09:12:18 UTC

gpu: AMD Radeon PowerColor rx 6600 Fighter
I have two displays connected LG 22" and Dell 27".
LG is connected via HDMI and Dell is connected via DisplayPort to HDMI cable.
Problem is with Dell monitor when enter suspend after timeout it immediately turn on again. 
When both displays are active suspend work but after second suspending. First both displays suspend and immediately turn on and after second timeout displays suspend again.
When just LG monitor is active suspend works fine.
I have tried to switch cables. When switch Dell to HDMI and LG to DisplayPort, Dell display suspend but LG turn on.
Also Dell monitor have black screen when play games on Steam.
If switch to LG to play, game works normally.
I played games on Sway and everything was fine.
 


STEPS TO REPRODUCE
1 . Wait for timeout to suspend displays  
2. Play game on steam

OBSERVED RESULT
1. Dell monitor turns off and on
2. Dell display black screen

EXPECTED RESULT
1. Display sleep
2. Play game normally

SOFTWARE/OS VERSIONS
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma:  Arch/plasma-desktop-6.3.3-1
KDE Plasma Version: 6.3.3
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

Comment 1 Nate Graham 2025-03-31 19:06:01 UTC

Does this happen on Wayland, or X11, or both?

Comment 2 v_jos 2025-04-02 05:52:03 UTC

(In reply to Nate Graham from comment #1)
> Does this happen on Wayland, or X11, or both?

It happens on Wayland and it started recently.
I played games without problems.
There was always problem with display sleep but no with gaming.
I will check X11.

Comment 3 v_jos 2025-04-02 06:04:34 UTC

(In reply to v_jos from comment #2)
> (In reply to Nate Graham from comment #1)
> > Does this happen on Wayland, or X11, or both?
> 
> It happens on Wayland and it started recently.
> I played games without problems.
> There was always problem with display sleep but no with gaming.

> On X11 display sleep normally but taskbar is missing after wake up.
> No black screen while gaming

Comment 4 v_jos 2025-04-02 06:06:15 UTC

(In reply to v_jos from comment #3)
> (In reply to v_jos from comment #2)
> > (In reply to Nate Graham from comment #1)
> > > Does this happen on Wayland, or X11, or both?
> > 
> > It happens on Wayland and it started recently.
> > I played games without problems.
> > There was always problem with display sleep but no with gaming.
> 
> > On X11 display sleep normally but taskbar and background image is missing after wake up.
> > No black screen while gaming

Comment 5 v_jos 2025-04-02 06:08:42 UTC

(In reply to v_jos from comment #4)
> (In reply to v_jos from comment #3)
> > (In reply to v_jos from comment #2)
> > > (In reply to Nate Graham from comment #1)
> > > > Does this happen on Wayland, or X11, or both?
> > > 
> > > It happens on Wayland and it started recently.
> > > I played games without problems.
> > > There was always problem with display sleep but no with gaming.
> > 
> > > On X11 display sleep normally but taskbar and background image is missing after wake up.
> > > No black screen while gaming

I installed full plasma package now just in case but nothing changed.