Bug 497764

Created attachment 176809 [details]
video showing problem with playing games on external display

SUMMARY
I'm observing a behaviour with playing some games on Fedora Kinoite wherein some games will just stop rendering entirely until you press the Super key to open the Application Launcher. When doing this, the game will render normally until you click into the window again. The game is still playing sound and seemingly responding to user input in this state. This doesn't happen in windowed mode however, and not with every day. This only happens when I have an external display connected to my laptop via HDMI, which is connected directly to the dGPU.

iGPU is an AMD Radeon 680M, and dGPU is an AMD Radeon RX 6800S.

A "fix" I have been using is to add "KWIN_DRM_DEVICES="/dev/dri/card1:/dev/dri/card2"" to /etc/environment, which forces the dGPU to take priority but results in terrible battery life when in hybrid mode, due to everything then running on the dGPU by default. The other workaround is to connect my external display via the left side USB-C port, which is connected to the iGPU.

I found one other person with the same model of laptop as me on the Majaro forum, with exactly the same issue (but using Manjaro instead) https://forum.manjaro.org/t/games-dont-render-on-external-monitor/172060

It doesn't seem to happen in all games, but the 2 I've noticed are both Unreal Engine 5 (Marvel Rivals, and Palworld). Could be because they're both DX12 titles. For good measure,  I also tried a DX9 game (The Elder Scrolls IV: Oblivion) and didn't observe the behaviour, and also an OpenGL game (Minecraft), also did not observe the behaviour.

Just for clarification, this doesn't happen with any games when using the internal laptop screen, as it is connected to the iGPu by default. I have not tried setting the GPU MUX to connect the display directly to the dGPU, but I presume the result would be the same.

STEPS TO REPRODUCE
1. Connect display to laptop with port connected directly to dGPU.
2. Launch Marvel Rivals
3. Once you get into the menu, start a practice match. As soon as the mouse cursor is hidden (due to gameplay), the game will stop rendering.

OBSERVED RESULT
Game appears to freeze

EXPECTED RESULT
Game should play normally

SOFTWARE/OS VERSIONS 

Linux/KDE Plasma: Fedora Kinoite 41
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.9.0
Qt Version: 6.8.1
Wayland

ADDITIONAL INFORMATION
I've attached a video to show the issue.