https://bugs.freedesktop.org/show_bug.cgi?id=103783
--- Comment #13 from Rene Barbosa renebarbosafl@gmail.com --- Hey,
Is your system using 'pcieport' module?
I've added it to RUNTIME_PM_DRIVER_BLACKLIST in TLP's configuration and now the problem is fixed!
Not sure why it's happening in Linux 4.13+ and not in 4.4 with AMDGPU-Pro installed.