Thumbnail and export artifacts with OpenCL and Radeon HD7870
I've had quite a few problems getting OpenCL to work on my system. Have a look here.
At the moment I am using proprietary driver 18.20 OpenCL only and open source radeon driver for the rest.
Using "export GPU_FORCE_64BIT_PTR=1" OpenCL gets detected by darktable and is used as well but produces serious artifacts in thumbnails and exported images (see attached files).
Artifacts are even produced with all modules disabled in darkroom. With OpenCL disabled everything works as expected.
Is there anything I can try to get rid of those artifacts other than disabling OpenCL?
Thank you in advance!