amdgpu-pro version 21.20 is already deleted from repo.radeon.com/amdgpu
This version known as the latest working version available for GCN 2.0 :
refs
- https://gitlab.freedesktop.org/drm/amd/-/issues/1806
- https://gitlab.com/illwieckz/i-love-compute/-/issues/6
originally from https://aur.archlinux.org/pkgbase/amdgpu-pro-installer with git tag 21.20_1271047-2. Thanks Andrew Shark
also https://aur.archlinux.org/packages/opencl-legacy-amdgpu-pro. Thanks HotrodMaster