Bug 493299

Summary:	Upon wake from sleep external monitors are no longer detected
Product:	[Plasma] kwin	Reporter:	Sollace <sollacea>
Component:	multi-screen	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	cwo.kde, nate
Priority:	NOR	Keywords:	multiscreen
Version First Reported In:	6.0.5
Target Milestone:	---
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed In:	6.2.0
Sentry Crash Report:
Attachments:	Output of dmesg -w

Description Sollace 2024-09-17 23:10:10 UTC

Created attachment 173806 [details]
Output of dmesg -w

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SUMMARY

Since updating my system a few days ago I've started seeing this issue.

Monitors will work fine, then when I unplug the monitor and the laptop is allowed to go to sleep, when waking again it will no longer detect any external monitors plugged into either USB-C port.

The problem persists across reboots and the only way I've been able to get them working is to do a full shutdown.

STEPS TO REPRODUCE
1. Boot and leave idle until the screen turns off
2. Plug the external monitor into a usb-c port

OBSERVED RESULT

USB connection works and devices and network connected through the monitors function, but no image is output to the monitor.

EXPECTED RESULT

Above but with video output to both monitors.

SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux 
KDE Plasma Version: 6.0.5
KDE Frameworks Version: 6.5.0
Qt Version: 6.7.2
Kernel Version: 6.11.0-rc4-7-MANJARO (64-bit)
Graphics Platform: Wayland

ADDITIONAL INFORMATION

My hardware is a HD ZBook with an nvidia GPU using the proprietary drivers. I've ruled out issues with the kernel and drivers by reverting temporarily to a stable/known working version and it hasn't resolved the issue.

My display setup is using a hp monitor connected into a USB-C port, with keyboard, mouse, and ethernet attached, and passthrough to a second monitor via a display port bridge.

It's not specific to the monitors as I have observed the same behaviour when plugging in my tablet display into the second usb-c port.

Comment 1 Sollace 2024-09-17 23:11:22 UTC

I originally filed this as a comment under https://bugs.kde.org/show_bug.cgi?id=400173 but was told to make a new bug report, so here we are :)

Comment 2 Nate Graham 2024-09-18 18:23:32 UTC

I can't find the bug report for this, but I'm preeeeeeeeeetty sure I recall this being a known issue that we fixed for Plasma 6.2. Closing for now. Do feel free to re-open this ticket if you're still experiencing the issue after upgrading to Plasma 6.2, though.

Thanks!