Alex Deucher sent in another pull request of new AMDGPU/Radeon DRM material for landing in DRM-Next to in turn make it into Linux 4.4.

Earlier this month AMD sent in their main DRM pull request that included the new AMDGPU GPU scheduler by default, new AtomBIOS opcodes, and other improvements.

Meanwhile, the primary addition with this second feature pull for DRM-Next is the new AMD Stoney APU open-source support. Stoney is the codename for a forthcoming APU due out in 2016. The code to enable Stoney support isn't too big since it's based on a Volcanic Islands GPU. You can find out more about Stoney via the aforelinked article as well as the forum comments over there.

Another change with this latest pull besides the Stoney support is increasing the VM default size to 64GB from 8GB. More details on this latest code that just landed can be found via the DRM-Next repository.

Sadly, not making it for Linux 4.4 is power management / re-clocking for the discrete GPUs with the AMDGPU driver thus the open-source performance with these latest graphics cards is very slow.