Compiz Crashed with SIGSEGV [Radeon]

[Liam McDonagh-Greaves]

Symptoms:
On login, the desktop takes a long time to load, and when it does, everything blinks. It is possible (but difficult) to open a terminal and execute commands, through the right-click desktop menu.

I first noticed the issue in mid-July of 2018.

System:
Acer 5100
Ubuntu 16.04 (64-bit)
Graphics card: VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RS482M [Mobility Radeon Xpress 200]

Possible red herring:
Believed to be mesa-related, as symptoms very similar to bug #1741447 and #1735594. I have been informed by a mesa developer that my issue is different because that bug affects Intel GPUs. This system has a Radeon GPU. Ubuntu reports it as a Compiz issue, so best to begin from there?

Note to developers: log files are as attached to bug #1795709. That bug was declared invalid by Apport because it says I don't have the necessary debug packages installed. However, I could not find the debug packages in the repository, so that is why I am submitting this report manually. Please tell me what you need and I will upload logs as required.

Many thanks for any help.

[Khurshid Alam (khurshid-alam)]

Looks like a graphics bug. Downgrade mesa. OR try in fresh install.

[Liam McDonagh-Greaves (maccydg)]

Thanks. Fresh install: same problems. I'm not an experienced user and I don't know how to downgrade mesa in a safe manner. I think it could make my system unusable if I get it wrong. How do I safely downgrade it?

[Daniel Daher (daher95)]

We had this same problem on ~100 PCs, all these computers had Ati Radeon X1200 graphic card and stopped working (Compiz Crash) on mid/later 2018.

To solve this issue we had to downgrade four mesa packages to a prior version:

libegl1-mesa:amd64
libgl1-mesa-dri:amd64
libwayland-egl1-mesa:amd64
mesa-vdpau-drivers:amd64

From version "18.0.5-0ubuntu0" to version "11.2.0-1ubuntu2".

In order to to this downgrade we did it this way (in case someone is interested on the how to):

apt-get install libegl1-mesa=11.2.0-1ubuntu2 libgl1-mesa-dri=11.2.0-1ubuntu2 libwayland-egl1-mesa=11.2.0-1ubuntu2 mesa-vdpau-drivers=11.2.0-1ubuntu2 -y --allow-downgrades

And we had them "hold" so the packages won't be updated on the future unless we do it manually:

    apt-mark hold libegl1-mesa
    apt-mark hold libgl1-mesa-dri
    apt-mark hold libwayland-egl1-mesa
    apt-mark hold mesa-vdpau-drivers

We are interested on an official release that repair this issue, if we can help debug this problem feel free to contact me.