Created attachment 179790 [details] A Photograph of the Black Display Visible after "Switch User" Has Been Invoked SUMMARY When I invoke "Switch User" (via Kicker, at least), I see a black screen, except for my cursor. I cannot interact with the OS afterward, even to send SysRq commands. Solely my MB's RESET_SW functions. STEPS TO REPRODUCE If you want to merely reproduce the uninteractibility, invoke "qdbus --system org.freedesktop.DisplayManager /org/freedesktop/DisplayManager/Seat0 org.freedesktop.DisplayManager.Seat.SwitchToGreeter". If you also want to reproduce the black screen, use "Switch User" (via Kicker – I really do want to test KRunner and the Application Menu too, but I don't want to hard-reset my OS frequently). OBSERVED RESULT When I invoke "qdbus --system org.freedesktop.DisplayManager /org/freedesktop/DisplayManager/Seat0 org.freedesktop.DisplayManager.Seat.SwitchToGreeter", the OS immediately becomes entirely uninteractible. When I invoke "Switch User" via Kicker, the same occurs, but the display also becomes black, except for the cursor. EXPECTED RESULT I should be sent to SDDM. SOFTWARE/OS VERSIONS I've provided the full output of KInfo, because IDK what's relevant to this bug: > Operating System: Fedora Linux 41 > KDE Plasma Version: 6.3.3 > KDE Frameworks Version: 6.12.0 > Qt Version: 6.8.2 > Kernel Version: 6.13.8-200.fc41.x86_64 (64-bit) > Graphics Platform: Wayland > Processors: 12 × AMD Ryzen 5 7600X 6-Core Processor > Memory: 30.4 GiB of RAM > Graphics Processor 1: AMD Radeon RX 5700 > Graphics Processor 2: AMD Radeon Graphics > Manufacturer: ASRock > Product Name: X670E Taichi Otherwise, because this is about SDDM, the undermentioned packages are installed: - sddm-0.21.0-6.fc41.x86_64 - sddm-breeze-6.3.3-1.fc41.noarch - plasma-desktop-6.3.3-1.fc41.x86_64 - plasma-workspace-6.3.3-1.fc41.x86_64 ADDITIONAL INFORMATION Originally reported at https://discuss.kde.org/t/switching-users-randomly-causes-black-screen-with-cursor/32103/7?u=rokejulianlockhart.
Hi - feel free to reopen if I'm missing something, but this seems like fundamentally the same issue as https://bugs.kde.org/show_bug.cgi?id=500038 - the code path followed by the "Switch User" option found by searching in Kicker doesn't work. *** This bug has been marked as a duplicate of bug 500038 ***
(In reply to John Kizer from comment #1) Didn't I demonstrate in the report that this isn't specific to Kicker? It occurs even when I invoke the relevant switch user command via QDBus.
Is there another part of the user interface that triggers the problem? The UI issue seems covered by the other bug - if you're wanting to report that there's a D-Bus method that triggers a freeze, that seems like a separate issue?
(In reply to John Kizer from comment #3) From what I recall, the issue which you've marked this as a duplicate of didn't cause a freeze. If I verified it does so via KRunner too, would that adequately differentiate them? Then, we'd have Kicker, QDbus, and KRunner all acting the same.
Setting aside the D-Bus stuff, the Kicker method is the KRunner method, correct - typing in "Switch User" to find it in search results? Is the issue that sometimes the Kicker/KRunner method causes a regular crash and sometimes a freeze-up, or is it that is used to do one and now does the other? Just trying to clearly delineate if there are distinct steps leading to issues, or the same steps with differing results. Thanks,
Created attachment 180147 [details] A Screencast of KRunner in Plasma 6.3.4 In retrospect, you might be correct. I'll post recordings of every reproduction method, and how the consequence of each differs, when they do.
Created attachment 180148 [details] A Screencast of Kicker in Plasma 6.3.4 (In reply to Roke Julian Lockhart Beedell from comment #6)
Created attachment 180149 [details] A Screencast of QDBus in Plasma 6.3.4 (In reply to Roke Julian Lockhart Beedell from comment #6)
When Plasma ≥ 3.4 reaches me, I'll try to remember to check whether the issue (at least with QDBus) remains reproducible.
*** Bug 486320 has been marked as a duplicate of this bug. ***
(In reply to Roke Julian Lockhart Beedell from comment #9) > When Plasma ≥ 3.4 reaches me, I'll try to remember to check whether the issue (at least with QDBus) > remains reproducible. John, this remains consistently reproducible (on the same hardware), despite https://bugs.kde.org/show_bug.cgi?id=500038#c10: > Operating System: Fedora Linux 42 > KDE Plasma Version: 6.3.4 > KDE Frameworks Version: 6.13.0 > Qt Version: 6.9.0 > Kernel Version: 6.14.2-300.fc42.x86_64 (64-bit) > Graphics Platform: Wayland I'm quite confident that this is separate to that bug.
That linked comment indicates that the fix for the issue will be released in Plasma 6.4.0 - I may be missing something, but that's not released yet and your device (like mine) is still using Plasma 6.3.4, so it seems logical that the issue wouldn't be fixed yet then?
...I misread my own Plasma version. IDK how. Please forget this ever happened.