Can you apply the following LLVM 2 code series, build the latest upstream libclc version, and try again? LLVM Patch series: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130812/184088.html http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20130812/184089.html Libclc: git clone http://llvm.org/git/libclc.git With that, and the latest mesa git code, I've managed to run bfgminer for ~5 minutes on a Radeon 5400 without a single lockup. This same GPU used to lock up within 5 seconds of starting: bfgminer -v1 --benchmark