[Post-Install] Random complete freeze when using KVM HDMI switch

[jlbo93]

Hello,

I am facing random complete freeze of Kunbuntu when using KVM HDMI switch. This happens with 25.10 but also with previous versions including LTS.

When the issue occurs, i don't have access to anything: keyboard, mouse... the only solution is to restart using power button. The problem can happen several times per day or not...

From the journal logs i get:

nov. 05 08:51:23 papadou kactivitymanagerd[2684]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:23 papadou polkit-kde-authentication-agent-1[2689]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:23 papadou plasmashell[2656]: kde.plasmashell: requesting unexisting screen available rect -1
nov. 05 08:51:23 papadou kded6[2627]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:24 papadou DiscoverNotifier[2942]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:24 papadou xdg-desktop-portal-kde[3189]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:24 papadou systemsettings[3067]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:24 papadou kdeconnectd[2902]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:24 papadou kwin_wayland_wrapper[2495]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::PlaceholderOutput(0x622284079db0, name="Placeholder-1", geometry=QRect(0,0 1920x1080), scale=1)
nov. 05 08:51:24 papadou kwin_wayland_wrapper[2495]: kwin_xwl: Could not find a matching X RandR CRTC/output to set as primary for KWin::PlaceholderOutput(0x622284079db0, name="Placeholder-1", geometry=QRect(0,0 1920x1080), scale=1)
nov. 05 08:51:24 papadou konsole[3066]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:24 papadou org_kde_powerdevil[2690]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:24 papadou plasmashell[2656]: qt.qpa.wayland: There are no outputs - creating placeholder screen
nov. 05 08:51:24 papadou org_kde_powerdevil[2690]: [  8913] Removing connected display on bus 1
nov. 05 08:51:24 papadou org_kde_powerdevil[2690]: [  8913] Emitting DDCA_Display_Status_Event[2986.607:  DDCA_EVENT_DISPLAY_DISCONNECTED, card1-HDMI-A-1, dref: DDCA_Display_Ref[11], io_path:/dev/i2c-1, ddc working: false]
nov. 05 08:51:24 papadou org_kde_powerdevil[2690]: [  8913] libddcutil callback thread 0x74fed8013440 started
nov. 05 08:51:24 papadou org_kde_powerdevil[2690]: [  8913] Started 1 event callback thread(s)
nov. 05 08:54:03 papadou rtkit-daemon[2300]: Supervising 10 threads of 7 processes of 1 users.
nov. 05 08:54:03 papadou rtkit-daemon[2300]: Supervising 10 threads of 7 processes of 1 users.
nov. 05 08:54:19 papadou PackageKit[8635]: daemon quit
nov. 05 08:54:19 papadou systemd[1]: packagekit.service: Deactivated successfully.​

How could this be fixed?

Thanks,

[abcdefgary]

I have this same issue and it is the reason i upgraded to 25.10. For posterity, I'm using the MLEEDA "Triple Monitor KVM Switch 3 Monitors 2 Computers" from Amazon.

I've been through replacing cables, docking station on the 2nd pc, and even the KVM switch. Nothing has fixed it and I am writing this comment from a laptop sitting on top of my desk since I cant switch to my desktop thanks to **gestures around at this post**

[jlbo93]

Hello,
Thanks for confirming i am not alone facing this issue. This happens with 25.10 too.

I have tried several different HDMI KVM switches with no luck. The freeze is random and i have no idea about the root cause. I have submitted a bug in the kde bug tracking system:
https://bugs.kde.org/show_bug.cgi?id=511988
I hope the devs will find out and get it fixed !

Thanks,