Going back months ago Valve had been looking to contract workers for working on the AMDGPU/RadeonSI driver, they hired a former Nouveau developer to begin working on the open-source AMD code, their plans to improve AMDGPU for VR, and last week seeing the first RADV Vulkan commit by a Valve Software developer.
Now Valve Linux developer Pierre-Loup Griffais who has been involved in much of these efforts made the infrequent tweet a short time ago, "Is anyone maintaining a list of Linux games that don't work on radeonsi? GL compatibility context, extensions Mesa won't implement, etc."
I'm not aware of any exhaustive list myself, but I know for sure there are many Phoronix readers in our forums aware of what Linux games are running into trouble with RadeonSI. So if you are, be sure to comment on this article in our forums and Griffais will almost surely see it. RadeonSI improved a lot in terms of speed and compatibility for Linux gaming in 2016, but there still are some titles not playing happy on this open-source driver for GCN GPUs.