(In reply to comment #26)
> After compiling the latest version of mesa from git, I'm still getting this
> bug with my Radeon HD 7950 spamming the system log.
> 
> [  372.835016] [TTM] Illegal buffer object size
> [  372.835019] [TTM] Illegal buffer object size
> [  372.835021] [drm:radeon_gem_object_create] *ERROR* Failed to allocate GEM
> object (0, 6, 4096, -22)
> 
> So it doesn't seem to be fixed for me at least.

You need to compile the 32 bit mesa packages you are using as well. It's must
easier to just install the oibaf PPA. I have no issues after the fix.