Enabling VRR regresses resolution & refresh rate options
Affected version
OS: Fedora Silverblue 40.20240321.n.0
Kernel: Linux littleboi 6.8.0-0.rc6.49.fc40.x86_64 #1 SMP PREEMPT_DYNAMIC Mon Feb 26 18:38:52 UTC 2024 x86_64 GNU/Linux
GPU: Radeon 7900 XT
Display: Samsung G95NC
Mutter: mutter-46.0-1.fc40.x86_64
Affects the Wayland session.
Bug summary
Prior to enabling VRR, Mutter was able to configure full native resolution (7680x2160) @ 240 Hz. This uses DisplayPort 2.1 with fixes in kernel version 6.8. This display is fully capable of VRR (marketed as "Freesync Premium Pro").
However, once VRR is enabled, mutter only advertises 59.99Hz:
Steps to reproduce
- Enable VRR feature flag:
gsettings set org.gnome.mutter experimental-features "['variable-refresh-rate']"
- Fully shutdown system (full poweroff, otherwise VRR doesn't show up as an option).
- Power on system, observe VRR option populates in
gnome-control-center
at ~59 Hz. - VRR enables successfully at degraded refresh rate (screenshot below).
What happened
Mutter does not expose full native resolution & refresh rate options with VRR enabled. Disabling the feature flag and power cycling does not bring back the previous options.
What did you expect to happen
240Hz should be an option.
Relevant logs, screenshots, screencasts etc.
Experimental feature enabled:
craigcabrey@littleboi:~$ journalctl --user -feu org.gnome.Shell@wayland.service
Mar 21 12:09:57 littleboi systemd[1480]: Starting org.gnome.Shell@wayland.service - GNOME Shell on Wayland...
Mar 21 12:09:57 littleboi gnome-shell[2004]: Running GNOME Shell (using mutter 46.0) as a Wayland display server
Mar 21 12:09:57 littleboi gnome-shell[2004]: Enabling experimental feature 'variable-refresh-rate'
[snip]