Can't enable ULMB 2 on Wayland

I have to agree with random-user00. It would be very inconvenient if you have to change flags (and reboot) every time you want to change it. I’m hoping that this is just a temporary solution. But for now I just want it to work at all (changing back and forth).

I agree with Steamvoker. Changing settings and rebooting every time is really inconvenient.

❯ sudo cat /sys/module/nvidia_modeset/parameters/conceal_vrr_caps                                                                                                                                                                                                                  
Y

~ as 🧙
❯ nvidia-smi                                                                                                                                                                                                                                                                       Fri Jun  6 11:00:47 2025
+-----------------------------------------------------------------------------------------+
| NVIDIA-SMI 575.57.08              Driver Version: 575.57.08      CUDA Version: 12.9     |
|-----------------------------------------+------------------------+----------------------+

Same result as the beta. ULMB2 greyed out. Broken feature.

Not only not working on wayland, but also stopped working on x11.

I have discovered that I have to rebuild initramfs for the change to take effect. It seems to work, but not entirely. What I mean is that the parameter changes, KDE’s VRR settings reflect that as well (as in the VRR settings appear/disappear), but the monitor sometimes fails to switch itself between the G-SYNC and Normal modes.

sudo mkinitcpio -P always does what is needed and every time been enough and that already happens when updating the drivers or kernel. It just doesnt work.

I tested it today, and seem to be working.

❯ nvidia-smi --version
...
DRIVER version      : 590.48.01

❯ kinfo                                                                                                                                                                                                                                                                                                 ...
Graphics Platform: Wayland

❯ sudo c /sys/module/nvidia_modeset/parameters/conceal_vrr_caps
Y

Feel free to close the ULMB2 thread.

I guess it is technically solved then. Did you have to rebuild your initramfs (and reboot) every time you changed it?