AMDGPU DRM-Next Driver Picks Up Support For Vega 20 "A1" Stepping
The current Linux 4.20 cycle appears to have good support for Vega 20 GPUs at least from our tracking without having any access to the GPUs for now, but it looks like the production graphics cards will be on a new "A1" stepping rather than A0 that was used for the bring-up of this first 7nm Vega GPU.
At least for the time being, the Vega 20 A1 ASICs require different PSP firmware from the A0 stepping and that requires a new check in the AMDGPU DRM kernel driver for determining what firmware to load. PSP in this context is the Platform Security Processor, which is controversial among open-source fans.
It looks like the A1 stepping is what will reach the markets early next year with the A0 firmware filename being renamed to "_old", but we have also been surprised before from odd behavior out of hardware vendors. Linux 4.21 will be out around March 2019 perhaps around the same time as the Radeon Instinct MI50/MI60 GPUs begin shipping or there's the possibility they have a unified PSP firmware by that point to accommodate both A0 and A1 GPUs and thus making this kernel patch redundant. Or to avoid the kernel bumping requirement, it should also be possible to just overwrite the older Vega 20 PSP firmware with the new A1 image as there appears to be no other driver changes required.
The patch doesn't reveal any other details about changes between the A0 and A1 hardware... Presumably it's not too much though as while it requires new PSP firmware, there is no other driver changes needed at least in the AMDGPU code's current form.
It was at this week's AMD Next Horizon event where they officially announced Vega 20 as the high-end Radeon Instinct MI50 / MI60 accelerators for HPC and deep learning workloads.