Newly installed Kubuntu 18.04 brokes after try to install amdgpu for RX 550

Submitted by Hic Sunt Dracones

Assigned to Default DRI bug account

Link to original bug (#110416)

Description

I tried install this driver for RX 550 (https://drivers.amd.com/drivers/linux/amdgpu-pro-18.50-756341-ubuntu-18.04.tar.xz) 3 times and after installation the system doesn't begin, it just hold on a black screen saying:

[ 8.6668039] ccp 0000:08:00:02: sev command 0x4 timed out, disabling PSP
[ 8.6668075] ccp 0000:08:00:02: SEV: failed to get status. Error: 0x0

In that screen system doesn't answer any command.
If I change to tty2 (ctrl+alt+f2) I could login on the terminal e do amdgpu-uninstall and reboot (it works one time) and system would start normally.

So I couldn't fix that I had to reinstall the hole system (Kubuntu).

Base-Board: GA-A320M-S2H
BIOS version: F24
CPU: Ryzen 5 2600
GPU: RX 550 4GT - MSI
RAM: 8Gb HyperX Fury
Font: Bluecase 500W