Bug 447680 - Crash in DrmPipeline::applyPendingChangesLegacy()
Summary: Crash in DrmPipeline::applyPendingChangesLegacy()
Status: RESOLVED WORKSFORME
Alias: None
Product: kwin
Classification: Plasma
Component: platform-drm (show other bugs)
Version: git master
Platform: Neon Linux
: NOR crash
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-12-30 08:05 UTC by Bharadwaj Raju
Modified: 2022-05-25 04:36 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Backtrace (16.01 KB, text/vnd.kde.kcrash-report)
2021-12-30 08:05 UTC, Bharadwaj Raju
Details
drm_info output (12.18 KB, text/plain)
2022-01-14 06:22 UTC, Bharadwaj Raju
Details

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Description Bharadwaj Raju 2021-12-30 08:05:01 UTC
Created attachment 144953 [details]
Backtrace

SUMMARY
kwin_wayland crashes on start on Neon Unstable. Backtrace attached.

KWin::DrmObject::getProp<KWin::DrmCrtc::PropertyIndex>(KWin::DrmCrtc::PropertyIndex) const (propIndex=KWin::DrmCrtc::PropertyIndex::VrrEnabled, this=0x0)

the this=0x0 part looks relevant?


SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.23.80
KDE Frameworks Version: 5.90.0
Qt Version: 5.15.3
Kernel: 5.11.0-43-generic

HARDWARE
GPU: Mesa DRI Intel G41
Comment 1 Zamundaaa 2022-01-11 10:41:57 UTC
Are you using RelWithDebInfo builds? The assert in src/backends/drm/drm_pipeline_legacy.cpp:88 should've fired if the crtc is nullptr.

Do you have an output that is disabled in the settings or automatically disabled by KScreen? While I can fix the crash, it would be good to know why the crtc is nullptr
Comment 2 Bug Janitor Service 2022-01-11 10:44:09 UTC
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/1860
Comment 3 Bharadwaj Raju 2022-01-11 10:56:58 UTC
(In reply to Zamundaaa from comment #1)
> Are you using RelWithDebInfo builds? The assert in
> src/backends/drm/drm_pipeline_legacy.cpp:88 should've fired if the crtc is
> nullptr.

Not sure actually. I use the Neon Unstable package, so whatever they use.

> Do you have an output that is disabled in the settings or automatically
> disabled by KScreen? While I can fix the crash, it would be good to know why
> the crtc is nullptr

No, I only have one single monitor.
Comment 4 Zamundaaa 2022-01-11 20:25:39 UTC
Hmm, there not being any crtc shouldn't ever happen then. Can you test the patch? I can't reproduce the crtc being nullptr
Comment 5 Bharadwaj Raju 2022-01-12 11:24:08 UTC
With the patch, kwin_wayland no longer crashes. However, now it seems to freeze on startup, i.e. no desktop is loaded, I don't see the hot corner edge effect, etc. That might be unrelated though.
Comment 6 Zamundaaa 2022-01-12 19:43:18 UTC
So you can still move the mouse, and start applications (through KRunner or sth)?
Comment 7 Zamundaaa 2022-01-12 21:40:29 UTC
Git commit 2564886f7f99be17c914f7657d6c5b4e186483d4 by Xaver Hugl.
Committed on 12/01/2022 at 21:23.
Pushed by zamundaaa into branch 'master'.

backends/drm: fix legacy crash

M  +2    -3    src/backends/drm/drm_pipeline_legacy.cpp

https://invent.kde.org/plasma/kwin/commit/2564886f7f99be17c914f7657d6c5b4e186483d4
Comment 8 Zamundaaa 2022-01-13 15:48:28 UTC
The output of drm_info could also be useful, even if KWin is not painting anything at all anymore (ssh in and execute it as root to get it in that case).
Comment 9 Bharadwaj Raju 2022-01-14 06:22:34 UTC
Created attachment 145446 [details]
drm_info output

(In reply to Zamundaaa from comment #6)
> So you can still move the mouse, and start applications (through KRunner or
> sth)?

The mouse isn't rendered, and global shortcuts and KRunner don't seem to work. Just black screen.

> The output of drm_info could also be useful, even if KWin is not painting anything at all anymore (ssh in and execute it as root to get it in that case).

Switched to another TTY and ran drm_info, output attached.
Comment 10 Zamundaaa 2022-04-25 14:02:14 UTC
Sorry, I completely forgot this bug report. There have been a lot of changes for legacy and how KWin assigns display resources to outputs, is this still happening?
Comment 11 Bug Janitor Service 2022-05-10 04:35:00 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 12 Bug Janitor Service 2022-05-25 04:36:00 UTC
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!