Comment # 4 on bug 1040857 from Hans de Jong

I added the dmesg outputs for kernel 4.10.13-1-default and 4.11.4-1-default.

With the 4.10 kernel everything works fine. With the 4.11.4-1-default kernel,
/sys/class/backlight/acpi_video0 shows up instead of
/sys/class/backlight/intel_backlight and brightness cannot be changed even when
changing the value of brightness in that directory.

I also installed kernel 4.12 from OBS, but that one boots into a black screen
with no messages.