Bug 506943

Summary:	Always keep VRR enabled on the driver side, only change the refresh rate
Product:	[Plasma] kwin	Reporter:	AdamKafei <ian.law>
Component:	platform-drm	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	CONFIRMED ---
Severity:	wishlist	CC:	roberth.sjonoy, xaver.hugl
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description AdamKafei 2025-07-12 10:11:31 UTC

SUMMARY
I'm asking for the option when using Adaptive Sync Always to have a sub-option to select a refresh rate bias; "High" to hold the refresh rate as high as the selected Display Configuration Refresh Rate option allows, possibly using the same code that is used now when Adaptive Sync is off but without switching the flag off(?) and "Low" to maintain the setting's current behaviour.

The reason I'm seeking this function is that per this: https://gitlab.freedesktop.org/drm/amd/-/issues/4046 when running Adaptive Sync Automatic my screen blacks out every time Adaptive Sync toggles (every time I alt+tab in or out of a game, every time I toggle fullscreen on a youtube or other video) and is therefore unusable and per this: https://bugs.kde.org/show_bug.cgi?id=477016 with the existing bias toward low refresh rates causes my screen to cycle through the refresh range, see: https://youtu.be/nj7FB1_pWw8 and produces a horrible flickering effect on account of the resulting brightness changes. I also accept the logic though of wanting to keep power costs down, hence asking for an option rather than a change so everyone can win.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 42
KDE Plasma Version: 6.4.2
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1

Comment 1 Roberth Sjonøy 2025-11-10 00:05:47 UTC

This would be really useful to have, currently kwin detects mpv as an application that should use adaptive sync, this causes some vrr flickering on my oled display when playing video with mpv.

Comment 2 Zamundaaa 2025-11-10 21:41:47 UTC

The refresh rate doesn't go down as a power saving feature, it's literally what adaptive sync means. If you don't want the refresh rate to go down, you should not use it.

What we can do for that driver / display bug (and for https://gitlab.freedesktop.org/drm/amd/-/issues/2200) is to make "Automatic" always enable it on the display side, and only change the refresh rate through some other means. Doing that in a reasonable way requires new driver APIs though, which have been discussed but noone's implemented them in the kernel yet.