(In reply to Brian Schott from comment #13)
> (In reply to Pierre-Eric Pelloux-Prayer from comment #12)
> > Does using "AMD_DEBUG=nodcc" Mesa environment variable help?
> 
> It does. Exporting that in my ~/.profile makes the desktop usable.
> 

Let's focus on this issue first.

Can you paste the output of: "AMD_DEBUG=info glxgears" please?

And would you be able to test other versions of Mesa to see if your issue could
be bisected (if it happens to be a Mesa problem)?