Bug 489367 - Connecting USB-C dock with external displays fails to activate them and gives a black screen
Summary: Connecting USB-C dock with external displays fails to activate them and gives...
Status: RESOLVED LATER
Alias: None
Product: kwin
Classification: Plasma
Component: platform-drm (show other bugs)
Version: 6.1.0
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-06-28 10:51 UTC by Massimiliano L
Modified: 2024-07-20 21:45 UTC (History)
1 user (show)

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


Attachments
Log from the crash (82.79 KB, text/plain)
2024-06-28 10:51 UTC, Massimiliano L
Details

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Description Massimiliano L 2024-06-28 10:51:38 UTC
Created attachment 171125 [details]
Log from the crash

SUMMARY
Sometimes (more often than not) when connecting a USB-C dock with two external displays, the two displays fail to activate. Whether the issue occurs seems totally random. Sometimes disconnecting and reconnecting the dock fixes the issue, sometimes multiple iterations are required. Sometimes restarting the system and/or plasmashell seems to help (but this is anectodal could still be random).

STEPS TO REPRODUCE
1. Connect USB-C dock with external displays
2. Configure display setup in "Display Configuration". In my case, the laptop screen is set to deactivated when the external displays are connected.
3. Work normally.
4. Disconnect dock and move on with your life.
5. Get back to work and connect the USB-C dock.

OBSERVED RESULT
Laptop display deactivates, but external display do not activate and stay black.

EXPECTED RESULT
External displays activate regularly upon connection.

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 40
KDE Plasma Version: 6.1.0
KDE Frameworks Version: 6.3.0
Qt Version: 6.7.1
Kernel Version: 6.9.5-200.fc40.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz
Memory: 15.5 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 620
Manufacturer: Dell Inc.
Product Name: Latitude 7490

ADDITIONAL INFORMATION
A system log is attached. This was taken on a fresh boot. At the first connection of the USB-C dock, the displays failed to activate. Disconnecting and reconnecting the dock fixed the issue at the first try. All this is captured in the log.
Comment 1 Massimiliano L 2024-06-28 10:54:42 UTC
P.S.: about the attached logs I should mention that, upon reconnecting the dock, the external displays reactivated but one of the two displays started at low resolution (640x480) and was not reachable with the mouse pointer (Display Configuration would show it as "detached" from the main display). Usually when the disconnect-reconnect iteration succeeds in activating the displays, those respect the configuration I had previously set.
Comment 2 Zamundaaa 2024-06-28 13:26:26 UTC
Please attach the kwin log
> journalctl --user-unit plasma-kwin_wayland --boot 0
and the output of drm_info
- without the dock connected
- with it connected and working
- with it connected and not working
Comment 3 Bug Janitor Service 2024-07-13 03:46:48 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 4 Massimiliano L 2024-07-20 08:05:04 UTC
(In reply to Zamundaaa from comment #2)
> Please attach the kwin log
> > journalctl --user-unit plasma-kwin_wayland --boot 0
> and the output of drm_info
> - without the dock connected
> - with it connected and working
> - with it connected and not working

Hi and thanks for the feedback.

Unfortunately, the USB-C port of my laptop is failing so I need to wait for a new one in order to properly test this. If the bug gets closed, I can reopen it whenever I have new information.
Comment 5 Zamundaaa 2024-07-20 21:45:36 UTC
(In reply to Massimiliano L from comment #4)
> Unfortunately, the USB-C port of my laptop is failing so I need to wait for
> a new one in order to properly test this. If the bug gets closed, I can
> reopen it whenever I have new information.
Okay, let's do that