| SUBSYSTEM=="i2c-dev", ACTION=="add",\ | |
| ATTR{name}=="NVIDIA i2c adapter*",\ | |
| TAG+="ddcci",\ | |
| TAG+="systemd",\ | |
| ENV{SYSTEMD_WANTS}+="ddcci@$kernel.service" |
Copied from https://gitlab.com/ddcci-driver-linux/ddcci-driver-linux/-/issues/7#note_151296583
With nvidia drivers, ddcci-driver-linux does not automatically create a backlight device.
A device can be created manually by doing:
$ echo 'ddcci 0x37' | sudo tee /sys/bus/i2c/devices/i2c-<number>/new_device
where is given by
$ ddcutil detect
This fix does this automatically when the i2c device is added.
| [Unit] | |
| Description=DDCCI Device auto-attachment (needed for NVIDIA) | |
| Before=shutdown.target | |
| Conflicts=shutdown.target | |
| [Service] | |
| Type=oneshot | |
| ExecStart=/bin/bash -c 'echo Attempting attach ddcci to %i && success=0 && i=0 && id=$(echo %i | cut -d "-" -f 2) && while ((success < 1)) && ((i++ < 5)); do /usr/bin/ddcutil getvcp 10 -b $id && { success=1 && echo ddcci 0x37 > /sys/bus/i2c/devices/%i/new_device && echo "ddcci attached to %i"; } || sleep 5; done' | |
| Restart=no |