Is the i915.ko module loaded?
lsmod | grep i915
Does it support your graphics hardware?
pciid=$(lspci -vnn | grep VGA | sed -re 's/^.*(8086):(....).*/v0000\1d0000\2sv/');
modinfo i915 | grep -iF $pciid
You may need to load the i915 driver with the preliminary_hw_support parameter set to 1
to get skylake support.
You can do this either from the kernel command line (i915.preliminary_hw_support=1)
or by putting an entry in /etc/modprobe.d/local-i915.conf:
options i915 preliminary_hw_support=1

hi,
I have compiled kernel4.2, which been intalled on skylake.when i run the modetest in libdrm,some error occurred:
trying to open device 'i915'...faile
In addition,There is nothing in /dev/dri/ directory.
what's the reason?