 With current driver stack, kernel 3.16-rc3, mesa-10.3-devel (up to commit    
370184e813b25b463ad3dc9ca814231c98b95864) and llvm 3.5 snapshot (svn svn212056)
on radeonsi (Radeon 8400), etc... much of this darkness in Trine 2 disappear...
i mean render much nearly correct :), only some little parts remain being black
:).