RADV developer Bas Nieuwenhuizen has wired in support for ETC2 texture compression to this Mesa-based, open-source Radeon Vulkan driver.

The textureCompressionETC2 device feature is now supported by the RADV driver with the latest patches. This ETC2 lossy texture compression support is handled by Radeon GPU hardware with Stoney Ridge APUs or Vega "GFX9" GPUs and newer, including Raven Ridge.

It took just a few dozen lines of code getting this ETC2 texture compression support in place, including for Vega, and mainly involved adding the proper formats. With ETC2 texture compression marked off the list, this just leaves ASTC texture compression, shader storage image multi-sample, and int16 support as the only VkPhysicalDeviceFeatures not currently possible with RADV.

The patch for now can be found on Mesa-dev but will likely find its way to Mesa 17.4-dev Git in the very near future.