Bug 479874

Summary:	Inconsistency in monitor identification potentially causing configurations to not apply correctly
Product:	[Plasma] KScreen	Reporter:	Nathaniel Mason <nathanielma5on>
Component:	common	Assignee:	kscreen-bugs-null <kscreen-bugs-null>
Status:	RESOLVED FIXED
Severity:	minor	CC:	nate, xaver.hugl
Priority:	NOR	Keywords:	multiscreen, qt6
Version First Reported In:	5.92.0
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:	6.0.5
Sentry Crash Report:

Description Nathaniel Mason 2024-01-15 23:16:48 UTC

Every time I launch Plasma with my external monitor plugged in, I get the standard popup for positioning new monitors. Regardless of which option I select it will only ever extend to the right. Trying to configure the monitor layout from Kscreen does work, but only until plasma is relaunched or the monitor is unplugged and replugged, at which point it acts as if the monitor has never been configured before. This behavior first occurred in Plasma 6 Beta 1.

When in Kscreen, the secondary display is labelled "Panascope Pixio PX248P", however when clicking the "Identify" button, the label on my external monitor shows as "HDMI-A-1-unknown". I don't recall this behavior being present prior to Plasma 6 Beta 1.

I suspect this disparity in how the monitor is being identified is leading to situations where the Kscreen config isn't applying correctly.

Linux: 6.7.0
KDE Plasma Version: 5.92.0
KDE Frameworks Version: 5.248.0
Qt Version: 6.7.0

Comment 1 Zamundaaa 2025-01-10 16:29:58 UTC

Sorry it took so long to get to this; are you still experiencing the issue?

If so, with the external monitor connected, please attach the output of
> kscreen-doctor -o
and
> drm_info
and the EDIDs of your displays, which you can get with
> cat /sys/class/drm/card1-HDMI-A-1/edid > edid.bin
(adjust connector name and bin file name according to your displays)
Also, are you on Wayland or Xorg?

Comment 2 Nathaniel Mason 2025-01-19 11:09:23 UTC

Apologies for not returning to resolve this sooner. This was on Wayland, and if I remember correctly, this bug stopped appearing for me somewhere fairly early in the 6.0.x cycle.

Comment 3 Nate Graham 2025-01-19 21:53:25 UTC

Thanks a lot for following up!