Comment 2 for bug 1760545

from the log file, we found glk_dmc firmware load failed.

I have tried this, seems GLK back to well.

Log:

test-NUC7PJYH:~ #dmesg | grep -i 'error\|fail\|unknown\|unsupport\|bad\|warning'
[ 1.985921] i915 0000:00:02.0: Direct firmware load for i915/glk_dmc_ver1_04.bin failed with error -2
[ 1.985924] i915 0000:00:02.0: Failed to load DMC firmware [https://01.org/linuxgraphics/downloads/firmware], disabling runtime power management.

You can download this dmc file from
https://01.org/sites/default/files/downloads/intelr-graphics-linux/glkdmcver104.tar_0.bz2

By the way, when you download this file, please use install.sh in the package to install the firmware, seems others files are needed.