I just updated to 470.57.02 from the OpenSUSE Tumbleweed repo. Prior to the update (and reboot) I was successfully using ddcutil to change the brightness of my two monitors, but now ddcutil detect only reports one of them:
Ddutil used to display two monitors, “DDC-Display” 1 used to be an HP ZR24w (DVI->HDMI cable connected), and DDC-Display 2 was my LG HDR 4K (displayport cable), but now ddutil only reports my LG display as DDC-Display 1. The only change was an update to the nvidia driver and a reboot (twice to check the problem would shake loose). In other respects the two monitors are working normally.
I found some old notes I had made, they had not been applied to this system:
- Nvidia enable i2c
- Needed for ddcutil - not really of any use at this point, but included for reference
- xorg.conf
Section "Device"
Identifier "Device0"
Driver "nvidia"
Option "RegistryDwords" "RMUseSwI2c=0x01; RMI2cSpeed=100"
VendorName "NVIDIA Corporation"
BoardName "GeForce GTX 1650 SUPER"
EndSection
- /etc/modprobe.d/99-local.conf and run ldconfig afterwards:
options nvidia NVreg_RegistryDwords=RMUseSwI2c=0x01;RMI2cSpeed=100
I applied them and now ddcutil reports both monitors:
For some reason, prior to kernel 5.13.2-1-default, nvidia and ddcutil was working without these config entries.
I actually rebooted to 5.13.1-1 to check and yes ddutil works without these settings (although the boot with the new 470 driver does actually make it to sddm).