Does not work with HP Zbook 15

[Np237]

Hi,

we have a bunch of HP laptops here, and nvidiabl works nicely with the 8560w (Quadro 1000M) and 8570w (Quadro K1000M).
However, with the newest Zbook 15 (Quadro K1100M) nvidiabl does not work.

The GPU is correctly detected, the module loads and you can change the brightness, it reflects in /sys/class/backlight/nvidia_backlight/brightness, but the actual brightness on the screen is not changed.

lspci reports:
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation Device [10de:0ff6](rev a1)

[jrstjohn]

nvidiabl does not work with the Dell Precision M4800 laptop either. I can manually load it via modprobe nvidiabl, but the brightness does not change using nvidiablctl or the Fn keys. Just like the problem you describe, the values in /sys/class/backlight/nvidia_backlight/brightness change, but the display's brightness never actually changes. The Precision M4800 has a Quadro K2100M, which I believe is in the same generation as the Quadro K1100M. I have the proprietary NVIDIA driver version 337.25 installed.

I created issue #98 to fix automatic loading, but that obviously won't fix the problems described here.