AMDGPU DP 2.0 MST Support Sent In For DRM-Next

AMDGPU changes already queued up in DRM-Next for Linux 5.16 brought initial code for DisplayPort 2.0 ahead of next-gen GPUs with this connectivity support. Sent out today as a separate pull request is wiring up the DisplayPort 2.0 Multi-Stream Transport (MST) capability for the AMDGPU kernel driver.

Sent in as a late topic branch is the AMDGPU DP 2.0 MST support along with a necessary change to the DRM common DisplayPort MST helper code. Multi-Stream Transport allows for multiple independent displays to be driven from a single DisplayPort output, AMDGPU has supported DP MST for DisplayPort 1.x, but additional changes are needed for DP 2.0 compatibility.

The DisplayPort 2.0 code queued up last month in DRM-Next is just around Single-Stream Transport (SST), but assuming this late PR is merged in time, MST will now be handled too for the AMDGPU driver in Linux 5.16. The PR is just over 400 lines of new code to get DP 2.0 MST in order for this open-source AMD Radeon GPU Linux driver.

In addition to the DisplayPort 2.0 bring-up, the AMDGPU driver in Linux 5.16 also is display support for the Cyan Skillfish APU, finally enabling PSR by default for new GPUs, USB4 DisplayPort tunneling with USB4 coming to Rembrandt, and a number of other additions. Linux 5.16 stable should be out around the start of the new year.