AMD "Navy Flounder" Support Merged Into Mesa 20.2

"Navy Flounder" as the codename for another Navi 2 GPU following the "Sienna Cichlid" Linux driver work has made it into Mesa 20.2 for the RadeonSI Gallium3D driver.

The Navy Flounder AMDGPU kernel driver support for Linux was sent out several weeks ago and will come with the Linux 5.9 kernel alongside the newly-enabled Sienna Cichlid support for these initial Navi 2 GPUs seeing open-source Linux driver support.

Merged a few minutes ago into Mesa 20.2, which is due for branching this week, is the Navy Flounder support. This allows the Navi 2 GPUs to have a working OpenGL driver in this quarter's Mesa3D stable release. The code today was around RadeonSI while the RADV support shouldn't be far behind considering the minimal code delta to Sienna Cichlid and Navi 1 for that matter.

The support amounts to adding the new PCI IDs, the Navy Flounder class, and adding it to the same code paths as Sienna Cichlid as well as for the AMDGPU LLVM GFX 10.3 target.

One interesting element is that displayable DCC (Delta Color Compression) is being unconditionally enabled now for all GFX10.3 parts and newer. With Navi 1, the display DCC support was flipped on for only Navi 12 and Navi 14.

Mesa 20.2 should be branched in the coming days while the stable release will be out in late August or early September. That though needs to go along with Linux 5.9 that will officially get underway in August but not see a stable release until October. For the AMDGPU LLVM back-end, Navi 2 needs LLVM 11.0 and that will see its stable release in September.