Bug 513601

Summary:	kwin choose higher refresh rate not support by default
Product:	[Plasma] kwin	Reporter:	Lemma <speedlemma>
Component:	output configuration	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	nate, nicolas.fella, xaver.hugl
Priority:	NOR
Version First Reported In:	6.5.4
Target Milestone:	---
Platform:	Kubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Lemma 2025-12-20 09:37:57 UTC

Product: kwin
Component: wayland
Version: 6.5.4

SUMMARY
On a system with an Intel i5-3470 (Ivy Bridge iGPU) running Kubuntu 25.10, KWin automatically selects 75Hz as the default refresh rate for a 1024x768 monitor connected via VGA. This causes the monitor to display an "Out of Range" error immediately upon login. While the monitor's EDID seems to incorrectly advertise 70Hz and 75Hz as supported, KWin chooses the highest available rate instead of a safe 60Hz default, rendering the system unusable without manual TTY intervention.

STEPS TO REPRODUCE
Connect a 1024x768 monitor via VGA to an Intel i5-3470 system.
Boot into Kubuntu 25.10 (Plasma 6.5.4).
Log in to the desktop session.

OBSERVED RESULT
The monitor immediately goes black and displays "Out of Range" because KWin has defaulted to 75Hz.

EXPECTED RESULT
KWin should either default to a safer 60Hz or provide a failsafe mechanism/cooldown period where it reverts to the previous setting if the user cannot confirm the new refresh rate.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kubuntu 25.10
KDE Plasma Version: 6.5.4
Windowing System: Wayland

ADDITIONAL INFORMATION
GPU: Intel HD Graphics 2500 (i5-3470)
Connection: VGA
Resolution: 1024x768
Note: The monitor's EDID is likely faulty as it claims to support 75Hz, but the OS should allow a way to force or prioritize 60Hz to prevent "Out of Range" lockouts.

Comment 1 Lemma 2025-12-20 10:43:18 UTC

this is specific to wayland, x11 session launched successfully, but i try wayland session monitor goes black and show out of range msg.

Comment 2 Zamundaaa 2025-12-20 14:04:23 UTC


*** This bug has been marked as a duplicate of bug 512146 ***

Comment 3 Lemma 2025-12-20 15:12:11 UTC

(In reply to Zamundaaa from comment #2)
> 
> *** This bug has been marked as a duplicate of bug 512146 ***

i am on 6.5.4 and still get error,
x11 session works, while wayland session still show out of range msg with black screen.
kwinoutput json file still show 75hz refresh rate when i show it from tty.
but when i launch x11 session this file get changed and shown 60hz.

i know its my monitor specific issue, not driver issue, my monitor show incorrect edid data, even in other desktop environments but other desktop environments works fine with my monitor even on wayland, because they default to 60hz or have any fallback mode.

i really want to use kde plasma because i like it a lot.

if this take time, please tell me any workaround.