OpenCL with the open-source AMDGPU driver

Update, 2018.06.28.
Kubuntu 18.04, AMDGPU-PRO 18.20-606296.

--compute has been deprecated. Instead, run:

    amdgpu-pro-install --opencl=legacy,pal --headless

Tested with Kubuntu 17.04, kernel 4.10, AMDGPU-PRO 17.10-414273, XFX Radeon RX-480 (Polaris/Ellesmere).

AMDGPU is a open source driver for AMD graphics. It is available in stock kernels starting with Linux 4.2, but does not provide OpenCL. OpenCL support for the newer AMD chips can be added by installing several libraries from the binary AMDGPU-PRO driver distribution, provided by AMD (AMDGPU-PRO itself only works with RHEL/CentOS 7.3/6.8, Ubuntu 16.04, SLED/SLES 12).

Check `lsmod` and /var/log/Xorg.log that you have AMDGPU loaded and working.

Download AMDGPU-PRO package for your Linux distribution from

`tar -xvf ...` to upack the downloaded file and run:

    amdgpu-pro-install --compute    (see Update above)
which is for “compute only”, i.e. it will install only the following:

Run clinfo to check OpenCL support.
Or run darktable-cltest :)

May 2017. Šarūnas Burdulis.