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ngoonee

Forum Fellow

From: Between Thailand and Singapore

Registered: 2009-03-17

Posts: 7,360

Erratic failure for external monitor activation

This has been going on for quite a while now intermittently, now trying to get to the bottom of it.

Laptop is a Lenovo Legion 5 Pro, I think the main important information is that its got a built-in AMD iGPU and a discrete NVidia card.

~  lspci -k | grep -A3 -E "VGA|3D"
01:00.0 VGA compatible controller: NVIDIA Corporation GA104M [GeForce RTX 3070 Mobile / Max-Q] (rev a1)
        Subsystem: Lenovo Device 3a4f
        Kernel driver in use: nvidia
        Kernel modules: nouveau, nvidia_drm, nvidia
--
06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Cezanne [Radeon Vega Series / Radeon Vega Mobile Series] (rev c5)
        Subsystem: Lenovo Device 3a4f
        Kernel driver in use: amdgpu
        Kernel modules: amdgpu

I'm using KDE and am on wayland. Everything seems to work once its working (and I have no issues with laptop-only), but multi-monitor has this regular annoyance where the external monitor is detected but either shows no signal or a frozen screen (black with just the KDE logo or just showing my background wallpaper and panel with no mouse interactivity).

The workaround is to log out and log back in. This does not necessarily fix it the first time, but doing it a few times I can normally get it to fully functional.

The full journalctl from my most recent boot is in this link (sorry for onedrive link, journal log is too big for most pastebins) - https://1drv.ms/t/c/905cfb71f92c7f7f/IQ … E?e=nePaIF

The first boot is from 7:18 to 7:19 (no signal on the external monitor). I waited a bit (so the timestamps would be easy to align) and then logged out and logged back in at 7:20 (signal detected but just a frozen black KDE logo). I waited and till 7:21 and then logged out and in to a functioning multimonitor setup.

There's a plasmashell crash in the 2nd login, this happens intermittently and is not directly correlated (it can happen even on 'good' logins, and it happening doesn't mean the next login will successfully activate the monitor). These crashes happen once in a while (only on login) for plasmashell, and doesn't seem to affect anything (also doesn't happen even though I use the laptop for days on end, only really triggers soon after login).

There are kwin_wayland errors which were previously reported here - https://bbs.archlinux.org/viewtopic.php?id=310531 - those appear to be related to PRIME (KDE bug report with no activity here - https://bugs.kde.org/show_bug.cgi?id=511852). I have not previously monitored for this error but the reports seem to say no ill effect from them. They also do show up both on failed and successful logins.

Besides those two errors I can't seem to find a journal difference between the successful login (7:21:xx) and the failed logins (7:19:xx and 7:20:xx). Anyone able to help? Sorry for the info-dump of the journal, I know its long, but I'm quite lost.

EDIT: After some more experimentation, killing plasmashell and logging out and in does seem to 'fix' the issue. Which is weird because crashing plasmashell sometimes happens even on successful logins (but only on boot). Suggestions for further debugging steps are appreciated.

Last edited by ngoonee (2026-01-11 12:28:32)

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