(In reply to K.-P. Schrage from comment #38)
...
> I put the two lines
> echo 1 >
> /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/hwmon/hwmon1/pwm1_enable
> /usr/local/bin/nvapoke e118 80000002
> into /etc/rc.d/rc.local (don't know any other way to make this workaround
> permanent).
> 

$ udevadm info -a -p /sys/class/drm/card0 | grep -m2
'ATTRS{device}\|ATTRS{vendor}'
    ATTRS{device}=="0xabcd"
    ATTRS{vendor}=="0x1234"

/etc/udev/rules.d/10-unladen-swallow.rules
ACTION=="add", ATTRS{vendor}=="0x1234", ATTRS{device}=="0xabcd", RUN+="/bin/sh
-c '/bin/echo 1 >
/sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/hwmon/hwmon1/pwm1_enable'",
RUN+="/usr/local/bin/nvapoke e118 80000002"