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Registered: 2024-09-20

Posts: 4

Switching to Wayland (Hyprland) from X11 (Plasma)

Unable to Start KDE Plasma After Switching from Hyprland (OpenGL Context Error)

Hi everyone, 

I am using Hyprland as my daily driver for everything. I tried gaming on it but faced issues with fluctuations and a lot of input lag. Due to this I am forced to use X11 for gaming. I use KDE Plasma for that.
However, I’m facing an issue when switching between Hyprland (Wayland) and KDE Plasma (X11).

Issue Description: 
- I boot into KDE Plasma (X11) → Everything works fine. 
- I log out of Plasma and start Hyprland (Wayland) → Everything works fine. 
- I log out of Hyprland and switch back to KDE Plasma → Plasma does not start properly.
- Instead, I get the error in a popup window: 
 

"Plasma is unable to start as it could not correctly use OpenGL 2 or software fallback. Please check that your graphics drivers are set up correctly."

- After this, the desktop just hangs.
- The only way to fix it is rebooting my system from another TTY.

What I’ve Tried: 
1. Restarting SDDM from another TTY: 
   

sudo systemctl restart sddm

 
   → No change. Plasma still fails to start. 

2. Killing lingering processes before switching to KDE: 
   

pkill Hyprland

 
   

pkill -9 Xwayland

 
   → Still doesn’t work. 

3. Manually starting Plasma from TTY: 
   

startx startplasma-x11

 
   → Returns:

 "Plasma is unable to start as it could not correctly use OpenGL 2 or software fallback. Please check that your graphics drivers are set up correctly." 

4. Checking GPU renderer:
   

glxinfo | grep "OpenGL renderer"

   - Shows correct GPU when running from a fresh boot.
   - Shows incorrect GPU or no output or No display found when Plasma fails to start.

System Info:
- Arch Linux (fully updated)
- KDE Plasma: X11 session
- Hyprland: Wayland session
- GPU: NVIDIA RTX 2060 Mobile
- Display Manager: SDDM
- Kernel: 6.6.72-1-lts

I'm on an ASUS ROG STRIX G15 Gaming laptop with Hybrid Graphics (Intel and NVIDIA).

Possible Causes (My Assumption):
- Hyprland might be leaving the GPU in an unusable state when switching back to X11.
- Plasma’s Xorg session fails to initialize OpenGL after using Wayland.
- NVIDIA/Intel GPU switching issue.

Questions: 
1. Has anyone else experienced this when switching between Wayland (Hyprland) and X11 (KDE)?
2. Is there a way to force Plasma to reset the OpenGL context without rebooting?
3. Any ideas on why a reboot fixes everything but restarting SDDM does not?

Any help would be greatly appreciated!