Since July, we’ve seen engineers from open source AMD drivers release code for “Cyan Skillfish” as an APU with Navi 1x graphics. While the initial Cyan Skillfish support has been merged for Linux 5.15, it turns out that the display code is not yet wired as it is a different DCN2 variant for its faceplate. .
Cyan Skillfish is in a bit of a strange position as it is a Navi 1x RDNA APU while other leaks / rumors have shown that AMD was going directly from existing Vega-based APUs to Navi 2x / RDNA2 and didn’t match. not to the other expectations of the roadmap. .. Especially with the AMDGPU Linux driver stack already busy preparing Yellow Carp / Rembrandt and Van Gogh. The fact that Cyan Skillfish is more of a custom APU design is that it has a slightly different display IP than existing RDNA / RDNA2 hardware.
The fixes released to enable support for the Cyan Skillfish display add support for the Display Core Next 2.01 “DCN201” display engine. This DCN 2.01 support comes after existing AMD graphics processors already have Display Core Next 2.1, 3.0. 3.01 and 3.02 variants.
AMD Renoir APUs with Vega graphics using DCN 2.1 IP, so it’s a bit annoying that Cyan Skillfish with Navi 1x reverts a bit to DCN “2.01” at least when it comes to conventional versioning. It is with RDNA2 that there is the DCN3 display engine.
In all cases, these patches the addition of 34,000 lines of new code due to the new DCN2 variant allows display output to work for Cyan Skillfish. As usual, much of the high row count is due to automated header files.
Given the timing and assuming there are no major flaws in this Cyan Skillfish display code, it should be merged later this year for Linux 5.16.