https://bugs.kde.org/show_bug.cgi?id=520842
[email protected] changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |[email protected] --- Comment #14 from [email protected] --- I can reproduce what looks like the same crash, but in a more severe variant: it happens on every login / compositor startup, not only intermittently on idle screen lock. Symptom: KWin segfaults immediately during compositor startup, restarts, and crashes again in a loop, so the Plasma session never comes up. ("Failed to start KDE Plasma Workspace.") Environment: - KWin / Plasma 6.7.0 (Wayland) - nvidia-open driver 610.43.02 (same as this report), DRM color pipeline support - CachyOS (Arch-based), kernel 7.0.12-1-cachyos (linux-cachyos) - The previous Plasma 6.6.5 stack on the exact same driver was unaffected; the crash started right after the 6.6.5 → 6.7.0 upgrade. Crashing thread backtrace (from coredumpctl, journald): kernel: kwin_wayland[1018]: segfault at 38 ip ... in libkwin.so.6.7.0[58c038,...] Stack trace of thread 1018 (kwin_wayland), SIGSEGV: #0 libkwin.so.6 + 0x58c038 #1 libkwin.so.6 + 0x584870 #2 libkwin.so.6 + 0x5c1521 #3 libkwin.so.6 + 0x5c3199 #4 libkwin.so.6 + 0x5c34e2 #5 libkwin.so.6 + 0x5b4c15 #6 KWin::DrmOutput::testPresentation(std::shared_ptr<KWin::OutputFrame> const&) (libkwin.so.6 + 0x5b5bef) #7 KWin::Compositor::setupLayers(...) (libkwin.so.6 + 0x1ab554) #8 KWin::Compositor::composite(KWin::RenderLoop*) (libkwin.so.6 + 0x1ae11b) #9 libQt6Core.so.6 + 0x1f081b #10 KWin::RenderLoop::frameRequested(KWin::RenderLoop*) (libkwin.so.6 + 0x2172b7) ... QCoreApplication event loop / QTimerInfoList::activateTimers ... This matches the path described here (Compositor::composite() → setupLayers() → DrmOutput::testPresentation() → DrmPipeline::testPresent() → color-op pipeline) and is triggered by the Qt render loop timer. The deeper frames (#0–#5) are unresolved in my dump (no debug symbols installed), but frame #6 DrmOutput::testPresentation plus the identical driver version 610.43.02 strongly suggest the same root cause in the new NVIDIA DRM color pipeline. Workaround confirmed: adding options nvidia-drm color_pipeline=0 (modprobe) and rebuilding the initramfs lets KWin 6.7.0 start normally. I'm happy to provide a fully symbolized backtrace if kwin-debug/debuginfod symbols would help — just let me know which frames are most useful. -- You are receiving this mail because: You are watching all bug changes.
