| Summary: | kwin crashes when monitors disconnected through dock | ||
|---|---|---|---|
| Product: | [Plasma] kwin | Reporter: | Chris <chris.esposito> |
| Component: | multi-screen | Assignee: | KWin default assignee <kwin-bugs-null> |
| Status: | RESOLVED FIXED | ||
| Severity: | crash | CC: | nate |
| Priority: | NOR | ||
| Version First Reported In: | 6.3.4 | ||
| Target Milestone: | --- | ||
| Platform: | Ubuntu | ||
| OS: | Linux | ||
| Latest Commit: | Version Fixed/Implemented In: | ||
| Sentry Crash Report: | |||
| Attachments: |
Output of journalctl --user --since "30 minutes ago" | grep -E "(kwin|wayland|EE)" during undock
Output of journalctl --user --since "30 minutes ago" | grep -E "(kwin|wayland|EE)" during undock Coredump from kwin_wayland during undock. |
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Created attachment 185094 [details]
Output of journalctl --user --since "30 minutes ago" | grep -E "(kwin|wayland|EE)" during undock
If something crashed, we need a backtrace of it so we can figure out what's going on. Can you please attach a backtrace of the crash using the `coredumpctl` command-line program, as detailed in https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl? Thanks! Created attachment 185150 [details]
Coredump from kwin_wayland during undock.
(In reply to Nate Graham from comment #2) > If something crashed, we need a backtrace of it so we can figure out what's > going on. Can you please attach a backtrace of the crash using the > `coredumpctl` command-line program, as detailed in > https://community.kde.org/Guidelines_and_HOWTOs/Debugging/ > How_to_create_useful_crash_reports#Retrieving_a_backtrace_using_coredumpctl? > > Thanks! Hi Nate, I just added a backtrace taken with coredumpctl. Thanks for taking a look! Chris Thanks. Unfortunately the backtrace is missing most of the debug symbols we need, most notably the ones from KWin. Please follow the instructions at https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports#Ubuntu-based_distros_(Ubuntu,_Kubuntu,_KDE_Neon,_Linux_Mint) to enable debug packages on your distro, and then get a new backtrace. I'm sorry this is an arduous process. Ideally distros would make this easy, or better yet, make it work properly out of the box! Thanks a lot! (In reply to Nate Graham from comment #5) > Thanks. Unfortunately the backtrace is missing most of the debug symbols we > need, most notably the ones from KWin. Please follow the instructions at > https://community.kde.org/Guidelines_and_HOWTOs/Debugging/ > How_to_create_useful_crash_reports#Ubuntu-based_distros_(Ubuntu,_Kubuntu, > _KDE_Neon,_Linux_Mint) to enable debug packages on your distro, and then get > a new backtrace. > > I'm sorry this is an arduous process. Ideally distros would make this easy, > or better yet, make it work properly out of the box! > > Thanks a lot! Sorry about that, I did attempt to install any necessary debug packages but it doesn't seem to be picking them up... I think we can close this though. This looks to have fixed in 6.4.5. I just installed system updates yesterday, and Plasma 6.4.5 came in from the Kubuntu Beta PPA, and I'm no longer having the issue on this version of Plasma. Thanks, Chris |
Created attachment 185093 [details] Output of journalctl --user --since "30 minutes ago" | grep -E "(kwin|wayland|EE)" during undock Note: Running Plasma 6.4.3 from Kubuntu Beta PPA. Debug symbols only available for 6.3.4, tried to take a trace with gdb, but I get `(No debugging symbols found in kwin_wayland)` SUMMARY KWin Wayland crashes when disconnecting any DisplayPort monitor on Intel TigerLake-LP GT2 with kernel 6.14.0. KWin crashes when disconnecting display from dock, or disconnecting dock from laptop. Was previously running Kubuntu 24.04.3, which was working fine. (Plasma 5.27 I believe), so I would imagine this was introduced in Plasma 6 when I upgraded to Kubuntu 25.04. STEPS TO REPRODUCE 1. Unplug a monitor (DisplayPort or HDMI) from HP USB-C or Thunderbolt docking station (have not tried other dock vendors) OBSERVED RESULT KWin crashes, KDE apps are restarted, but all other apps remain closed. EXPECTED RESULT Screen layout changes and app remains open SOFTWARE/OS VERSIONS Operating System: Kubuntu 25.04 KDE Plasma Version: 6.4.3 (from Kubuntu Beta PPA), but the issue was present on the Plasma version included in 25.04 KDE Frameworks Version: 6.14.0 Qt Version: 6.8.3 Kernel Version: 6.14.0-29-generic (64-bit) Graphics Platform: Wayland Processors: 8 × 11th Gen Intel® Core™ i5-1135G7 @ 2.40GHz Memory: 64 GiB of RAM (62.5 GiB usable) Graphics Processor: Intel® Iris® Xe Graphics (Intel TigerLake-LP GT2 Iris Xe Graphics (device ID 9a49)) Manufacturer: HP Product Name: HP ProBook 650 G8 Notebook PC System Version: SBKPF ADDITIONAL INFORMATION Issue does not occur with a monitor attached directly to the laptop HDMI port. Logs attached are of an undock event at 2025-09-19 08:00. journalctl.log is output of `journalctl --user --since "30 minutes ago" | grep -E "(kwin|wayland|EE)"` `dmesg -w` shows: 1426 │ [ 75.352419] thunderbolt 0-1: device disconnected 1427 │ [ 75.367135] pcieport 0000:00:07.0: pciehp: Slot(0): Link Down 1428 │ [ 75.367190] pcieport 0000:00:07.0: pciehp: Slot(0): Card not present 1429 │ [ 75.367255] pcieport 0000:02:04.0: Unable to change power state from D3hot to D0, device inaccessible 1430 │ [ 75.370300] pcieport 0000:02:04.0: Runtime PM usage count underflow! 1431 │ [ 75.370540] xhci_hcd 0000:03:00.0: remove, state 1 1432 │ [ 75.370612] usb usb6: USB disconnect, device number 1 1433 │ [ 75.370634] usb 6-1: USB disconnect, device number 2 1434 │ [ 75.370653] usb 6-1.3: USB disconnect, device number 3 1435 │ [ 75.370672] r8152-cfgselector 6-1.3.3: USB disconnect, device number 4 1436 │ [ 75.371316] xhci_hcd 0000:03:00.0: xHCI host controller not responding, assume dead 1437 │ [ 75.524654] xhci_hcd 0000:03:00.0: USB bus 6 deregistered 1438 │ [ 75.524708] xhci_hcd 0000:03:00.0: remove, state 1 1439 │ [ 75.524726] usb usb5: USB disconnect, device number 1 1440 │ [ 75.524732] usb 5-1: USB disconnect, device number 2 1441 │ [ 75.524737] usb 5-1.3: USB disconnect, device number 3 1442 │ [ 75.524741] usb 5-1.3.5: USB disconnect, device number 6 1443 │ [ 75.753192] usb 5-1.3.7: USB disconnect, device number 7 1444 │ [ 75.859260] kwin_wayland[4412]: segfault at 3c0 ip 000071a385944c6b sp 00007ffec4f3d330 error 4 in libkwin.so.6.4.3[544c6b,71a3855ae000+551000] likely on CPU 0 (core 0, socket 0) 1445 │ [ 75.859286] Code: 6b 60 e8 a8 2a cc ff 48 8d 7b 68 b9 62 00 00 00 48 c7 45 a8 00 00 00 00 48 89 c6 48 8d 05 bd 00 00 00 48 c7 45 b8 00 00 00 00 <f3> 48 a5 48 89 45 a0 48 8d 05 c7 ce cb ff bf 20 00 0 │ 0 00 48 89 45 Steps to Reproduce 1. Connect external monitor via Thunderbolt dock (DisplayPort) 2. Ensure monitor is working and detected properly 3. Physically disconnect the monitor cable from the dock 4. KWin immediately crashes Expected Behavior Monitor should disconnect cleanly without crashing the compositor. Applications should remain running. Actual Behavior - KWin crashes immediately upon monitor disconnect - All Wayland-native applications crash (Firefox, Chrome, Teams, DataGrip, OnlyOffice) - KDE applications survive - System automatically restarts KWin after crash Hardware Detection ``` [ 10.440714] i915 0000:00:02.0: [drm] Found tigerlake/uy (device ID 9a49) integrated display version 12.00 stepping C0 [ 10.507838] i915 0000:00:02.0: [drm] Finished loading DMC firmware i915/tgl_dmc_ver2_12.bin (v2.12) [ 10.575607] [drm] Initialized i915 1.6.0 for 0000:00:02.0 on minor 1 ``` Applied Kernel Parameters Tried adding the following with no change in outcome. Logs are from system WITHOUT these parameters present. ``` i915.enable_psr=0 i915.enable_dc=0 intel_idle.max_cstate=2 processor.max_cstate=2 ``` KWin Environment Variables Tested Tried adding the following, without any change in outcome. Logs are from system WITHOUT these added. ``` KWIN_DRM_NO_AMS=1 KWIN_FORCE_SW_CURSOR=1 KWIN_DRM_USE_ATOMIC=0 QT_LOGGING_RULES="kwin_*.debug=true" ``` Reproducibility: 100% - crash occurs on every single monitor disconnect Scope: Affects both single monitor disconnects from dock and full dock undocking, but not directly attached monitor being disconnected from laptop. Attempted Solutions Intel driver parameters: Applied standard TigerLake stability parameters - no effect KWin configuration: Disabled atomic mode setting, various environment variables - no effect Plasma upgrade: Upgraded from 6.3.4 to 6.4.3 - issue persists Hardware testing: Issue occurs with both USB-C and Thunderbolt docks and monitors. Additional Context - Issue did not exist on Ubuntu 24.04.3 with Plasma 5.27.11. I first noticed it after upgrading to 25.04 Plasma 6.3.4 (same kernel version). - All monitors work correctly when connected, disconnecting one via undocking, or by disconnecting a monitor from the dock causes the crash - KDE applications survive crash better than non-KDE applications - System otherwise stable, no other graphics issues