RADV's ACO Compiler Back-End Now Supported For Older AMD "Sea Islands" GPUs

The Valve-backed "ACO" compiler back-end for the open-source Radeon "RADV" Vulkan driver has added support now for AMD GCN 1.1 "Sea Islands" graphics cards.

Sea Islands includes the Radeon Rx 200 series with the R7 260/260X/290/295 series and these 2nd Gen GCN GPUs also ended up in the Radeon HD 7790, Radeon HD 8770, Radeon R7 360, Radeon R9 390/390X, and Radeon RX 455. Up to now the ACO compiler back-end has only supported GCN1.2/GFX8 and newer but with the latest Mesa 20.0-devel code as of today in Mesa Git there is now ACO support for GCN 1.1 Sea Islands.

Of course, to use the RADV Vulkan driver in first place with GCN 1.1 hardware you first need to be booting the system with "radeon.cik_support=0 amdgpu.cik_support=1" module parameters in order to default to the AMDGPU kernel driver for RADV support as the default Radeon kernel driver for GCN 1.1 and older does not support the interfaces needed for RADV. We haven't heard any AMD discussions in a number of months about plans for shifting GCN 1.1 (and GCN 1.0) to AMDGPU DRM by default.

In any case, try Mesa Git this weekend thanks to this MR for ideally delivering faster Vulkan performance now for older GCN 1.1 Sea Islands graphics cards. If there is enough interest, I'll fire up some new GCN 1.1 tests soon.