Arch Linux

kotv

Member

Registered: 2022-10-22

Posts: 4

Brightness steps are inaccurate with Nvidia cards on Waayland

Hello guys,

I installed Arch (latest ISO) and Hyprland on a laptop with an Nvidia card.

Almost all is working fine but when I try to change my display brightness a strange behavior happens.

I installed brightnessctl and configured my Hyprland.conf as follow:

bind=,XF86MonBrightnessUp,exec,brightnessctl -q set +5%
bind=,XF86MonBrightnessDown,exec,brightnessctl -q set 5%-

Starting from 0% brightness what happens is that

cat /sys/class/backlight/nvidia_0/brightness

shows:
0 -> Result in lowest brightness
I hit once the key to increase brightness and it shows
5 -> Results in what looks like 50%
One more hit and...
10 -> Results in the highest brightness
Next hit...
15 -> Looks like 15% I think, but not sure, it's too similar to the first one
All the next hits follow a correct increase of brightness

I also noticed that if I change the Hyprland.conf to increase and decrease of 1pt instead of 5% at a time, it works flawlessy well with steps of 10%, obviously for the first 10 strokes, but next it starts again from low brightness and increase by 1 pt (so in an endless run to reach 100%).
It looks like something (I don't know what component) is calculating the brightness by dividing the value of max_brightness with the value of brightness files inside /sys/class/backlight/nvidia_0/
The max_brightenss file contains 100 and is not possible to change that value, neither with sudo privileges

I installed the following nvidia related packages

paru -Qs nvidia
local/egl-wayland 2:1.1.11-3
    EGLStream-based Wayland external platform
local/hyprland-nvidia-git r2433.287f3132-1
    A dynamic tiling Wayland compositor based on wlroots that doesn't
    sacrifice on its looks. (NVIDIA patch)
local/lib32-nvidia-utils 525.89.02-1
    NVIDIA drivers utilities (32-bit)
local/libvdpau 1.5-1
    Nvidia VDPAU library
local/libxnvctrl 525.85.05-1
    NVIDIA NV-CONTROL X extension
local/nvidia-open-dkms 525.89.02-2
    NVIDIA open kernel modules
local/nvidia-settings 525.85.05-1
    Tool for configuring the NVIDIA graphics driver
local/nvidia-utils 525.89.02-1
    NVIDIA drivers utilities
local/nvidia-vaapi-driver-git 0.0.8.r63.g766d843-1
    A VA-API implemention using NVIDIA's NVDEC

Someone knows a way to fix that?