[1035724.274610] [drm:intel_pipe_update_end [i915_bpo]] *ERROR* Atomic update failure on pipe A (start=62076478 end=62076479) time 102 us, min 894, max 899, scanline start 893, end 900
W: Possible missing firmware /lib/firmware/i915/kbl_dmc_ver1.bin for module i915_bpo
I've been getting those errors on a J3455 NUC box with the latest kernel on Linux Mint 18.2. When updating the initramfs I also got the error about the firmware included.
In general it looks like there is a lack of Linux support or a bug in the driver and this seems to cause the screen to go blank/black and lockup after a few days. The system itself is running and available by SSH.
As a temp fix you can run this:
sudo service mdm restart but be warned this will result in all of your programs closing that were running so unsaved changes would be lost. The above command will restart mdm and allow you to login and work as normal again.