Radeon DisplayPort MST Queued For Linux 4.1
David Airlie of Red Hat had been working on DP MST support within the Linux DRM drivers for a while and after getting the Intel code squared away he moved on to the Radeon driver as talked about in recent Phoronix articles. The Radeon DisplayPort MST code is now into shape and is queued up in DRM-Next for ultimately being merged into Linux 4.1.
DisplayPort Multi-Stream Transport (DP MST) is important for newer 4K/5K monitors that expose themselves as two DisplayPort connections as well as some newer hardware like ThinkPad docking stations that rely upon this technology for multi-monitor support.
While the open-source Radeon DP MST support will appear in Linux 4.1, it's disabled by default. Other early Linux 4.1 changes for Radeon include non-ATOM AUX support, new profiling / Gallium HUD queries, and other fixes. This batch of Radeon updates was pulled in last night to DRM-Next. Sadly there's still no word on the new AMDGPU kernel driver.