When I use AMD GPU pro 18.40 driver with kabylake-g(Vega M GPU), The display
can work but I can't enter the GUI. Everytime when I enter the password to log
into the GUI desktop, the X-window will crash. When I switch to 18.40 open
stack driver, it works OK.

Following is my environment
CPU: Intel(R) Core(TM) i7-8809G CPU
GPU: Vega M(device ID: 694c)
OS: Ubuntu 16.04
Kernel: 4.18.0-rc3
Driver: AMD 18.40 Pro driver