Recently upgraded my machines to 18.04. I'm having a distortion problem on the screen now. It looks like lines running across the screen. The graphics are distorted a bit. I also notice that on boot the boot spam is large and not proper resolution. Before on 16.04 it would shrink after a minute to the proper resolution.

I think I'm having a firmware or driver issue here but I'm unsure how to proceed. I've tried stock, and hwe packages. I've also tried upgrade from 16.04 as well as fresh installations.

Amd Kabini APU HD8000 gpu on Ubuntu 18.04.

My guess is a problem with what information your monitor is reporting. Try running the get/parse EDID tools. You can get them from here. You can run xrandr to find what resolution your desktop is trying to run.

Ok thanks. I have 16.04 running on my server now. These are pxe booted machines. I have narrowed it down to just one machine / screen. The other doesn't seem to have the problem. Different tvs. I created an 18.04 kvm virtual machine and am pxe booting the one off of that for now so I can test and work it out. I will report back. Thank you.

I was only testing the one because it gets used 99% of the time in our bedroom. Other is only guest room. Won't be able to really work on it till tomorrow when the wife is at work.

Included is a diff made into a patch between Xorg logs on boot. The 1604xorg log everything boots fine every time. The 1804 log is from a recent boot where I have the lines running across my screen and the display is distorted. I don't know anything about what I'm reading here or how to isolate the problem. I'm hoping someone can help with this and assist me in finally finishing my 18.04 upgrade.

https://paste.ubuntu.com/p/kDX5bcrM29/

This paste is difference between the failed 18.04 boot above, and a successful boot. What makes this problem highly irritating is that it isn't consistent. It seems random, 50-60% of the time it fails

https://paste.ubuntu.com/p/NbrvRrZ4Vf/

Removed timestamps from both.