DC Display Support Continues To Be Worked On For Radeon GCN 1.0 With AMDGPU Driver

On top of the recent UVD video decode for AMD Radeon "GCN 1.0" GPUs with the AMDGPU kernel driver to complement the existing Radeon kernel driver support, these aging "Southern Islands" graphics cards also continue to see patchwork on enabling "Display Core" (DC) display support with the AMDGPU driver option.

A new round of patches were sent out today for enabling AMDGPU DC support for GCN 1.0 GPUs in this modern driver alternative to the classic "Radeon" DRM driver. DC is the display code used by modern Radeon GPUs and is shared with their Windows driver. GCN 1.0 supporting DC would allow usage of this unified code path and potentially supporting some new features or at the very least using this more properly tested code path. DC was formerly known as DAL prior to being upstreamed in the kernel and going through a major rework.

27 patches provide this "proof of concept" DC support for GCN 1.0. It remains to be seen if/when the patches will be deemed ready for upstream inclusion.

GCN 1.0 (and GCN 1.1 Sea Islands) graphics cards on Linux continue defaulting to the Radeon DRM driver rather than AMDGPU. Changing the drivers on modern kernels requires the radeon.si_support=0 radeon.cik_support=0 amdgpu.si_support=1 amdgpu.cik_support=1 module parameters so AMDGPU will be used for both GCN 1.0 and 1.1 era GPUs. In general the AMDGPU support for these older generations is in good shape on the driver (and in some cases faster for gaming) especially with UVD support now ironed out while using this AMDGPU kernel driver is also a requirement for Vulkan support on these original GCN graphics processors.