I recently upgraded to the latest AMD drivers (13.1) after prolonged suffering and now clGetDeviceIDs no longer finds my GPU.
I updated Xorg first, which broke, and after I purged the earlier AMD drivers from my system (they did not purge completely, no matter what I tried, I had to uninstall the old and install the new with --force) I installed 13.1.
I couldn't open Catalyst because of some libGL.so.1 issue, so I used aptitude to install anything fglrx-related (I selected NO when prompted to overwrite my manual installations - actually it was from the .run script provided on the AMD site).
Finally the display works again, but now OpenCL is not working properly.
What can I do?