Bug 478231

Summary:	On system with nvidia dGPU, external monitor turns black with only cursor shown after suspend to ram
Product:	[Plasma] kwin	Reporter:	fanzhuyifan
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	grave	CC:	nate, postix, roman, whelanh
Priority:	NOR	Keywords:	qt6
Version:	git master
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Attachments:	kwin log

Description fanzhuyifan 2023-12-07 21:55:10 UTC

SUMMARY
***
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***


STEPS TO REPRODUCE
1. connect external monitor
2. suspend to ram
3. wake again 

OBSERVED RESULT
1. external monitor is blank with only cursor shown. The cursor can be moved

EXPECTED RESULT
External monitor works.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.90.0
KDE Frameworks Version: 5.246.0
Qt Version: 6.6.1
Kernel Version: 6.6.4-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 20 × 13th Gen Intel® Core™ i9-13900H
Memory: 15.2 GiB of RAM
Graphics Processor: Mesa Intel® Graphics
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: ROG Zephyrus G16 GU603VV_GU603VV
System Version: 1.0

ADDITIONAL INFORMATION
System is intel iGPU+nvidia dGPU
This happens both with and without configuring nvidia PreserveVideoMemoryAllocation.
Without PreserveVideoMemoryAllocation disabled, this only seems to happen if I wait a long time after suspend.

When this happens, and I suspend the computer again, the external display typically starts working again after the next wake.

This only happens with one external display I use, and not the other one.

Possible duplicate of 477738.

Comment 1 fanzhuyifan 2024-01-29 17:44:04 UTC

Right now I don't even see the cursor -- my external display says no signal detected, entering power savings mode.

Comment 2 fanzhuyifan 2024-01-29 17:44:18 UTC

Created attachment 165325 [details]
kwin log

Comment 3 fanzhuyifan 2024-02-22 01:35:14 UTC

(In reply to fanzhuyifan from comment #1)
> Right now I don't even see the cursor -- my external display says no signal
> detected, entering power savings mode.

This also sometimes happens when the display turns off during idle, without suspending to ram.