Hi! I'm writing this email because I'm currently finishing up removing pretty much all of the non-atomic MST code in drm_dp_mst_topology_mgr.c as it's really made it difficult to maintain MST over time. As well, once that's complete it's likely I'm going to start on the (extremely overdue) task of moving as much of amdgpu's MST code for DSC out of amdgpu and into the DRM code where it's supposed to live.
This brings me to two questions. The first major one being: is anyone capable of testing the MST support in radeon.ko to figure out whether it works or not? I've already talked with hwentlan and ag5df about this and they haven't been able to find anyone to help with testing this. The reason I ask is because radeon isn't an atomic driver, and is basically the only user of any of the non-atomic parts of the MST helpers. If anyone want to prevent this from breaking in the future, I would definitely recommend they step up to try and help with testing it - otherwise I'm probably going to be pushing for us just to drop the code entirely.
The second question is: is anyone willing to help me figure out how much of the code in amdgpu related to DSC is definitely not amdgpu specific and can be moved out? I'm honestly having a lot of trouble wrapping my head around how some of this works, and how much of this code is even needed. As well, with the amount of issues I've already found in it (there's numerous spots where we're storing MST state outside of atomic state for instance, lots of duplicates of DP helper functions that should not be here, etc.) it's quite likely I'm going to be rewriting rather large chunks of it. If anyone would like to volunteer please let me know, it'd be super appreciated and likely will make reviewing the patches that will come out of this easier.