I'm currently working on an ASUS GL702VMK. This machine is shipping a GeForce
GTX 1060 GP106 (136000a1) connected to an internal DisplayPort on DFP-5 (usual
AU Optronics Corporation).

Using the unmodified latest nouveau drivers I have no backlight control.
Modifying nouveau_backlight.c adding a case for NV_DEVICE_INFO_V0_PASCAL I
finally get /sys/class/backlight/nv_backlight/ but changing the backlight value
in there is not working anyway.

Trying to manually poke NV50_PDISP_SOR_PWM_CTL(1) with `nvapoke` has no effect
whatsoever on the brightness (on or==1)

Backlight control is not working using the proprietary 375 / 378 drivers
either. Also in this case the value of NV50_PDISP_SOR_PWM_CTL is actually
changed by `xbacklight` but with no visible effect.

Any hint?