I have issue with AMD radeon PRO SSG with Linux
I have two Radeon Pro SSG on Dell Precision T7600, and they work correctly with Windows 10.
But for linux, I can only boot with recovery mode.
And when I try to install the driver, it says that "WARNING: nomodeset detected in kernel parameters, amdgpu requires KMS, WARNING: amdgpu dkms failed for running kernel".
When I try normal boot, the screen shows the black screen, and nothing proceeds.
I followed the instructions of following web pages, and nothing worked.
https://support.amd.com/en-us/kb-articles/Pages/Radeon-PRO-SSG-Setup-Under-Linux.aspx
https://support.amd.com/en-us/kb-articles/Pages/Installation-Instructions-for-amdgpu-Graphics-Stacks...
https://support.amd.com/en-us/kb-articles/Pages/AMDGPU-PRO-Install.aspx
I tried Ubuntu 16.04.2 Ubuntu 18.04, and also tried different kernel version (4.4.0, 4.15, 4.16, 4.17).
Is there anyone who knows how to resolve the issue?