No, Arch doesn't seem to apply that patch. But I am still using kernel 3.12.9, should it be there too? Also, that bug report was reopened on the 19 Dec, but I think (I may be wrong) I recompiled mesa after that and didn't see anything wrong. And compiling without --enable-r600-llvm-compiler doesn't help either. If I can help with anything else, just ask. Thanks