More AMDGPU DC Patches Posted As It Looks Unlikely It Will Land For Linux 4.13

Another set of 27 patches were posted today for AMDGPU's DC (formerly DAL) display stack, but it's looking increasingly unlikely that this code will be merged for Linux 4.13.

Harry Wentland of AMD today posted 27 more patches for this display stack. The latest work includes universal cursor plane support, many Raven Ridge APU fixes (Zen + Vega APU, coming later this year) -- including Raven Ridge stereo display support and DCN clock-gating, and various fixes. This is about another thousand lines of codes changes for this massive AMD display stack that's long been in development.

These latest DC patches come after AMD already submitted its main Radeon/AMDGPU pull for Linux 4.13 by way of DRM-Next. There's still just a week or two that new feature material will be accepted in DRM-Next for in turn landing in Linux 4.13 merge window (as David Airlie's been more strict now about getting material in -next early, especially big invasive feature work like DC), and thus it's looking very unlikely DC is going to make it for the next kernel round -- especially that the massive patch series hasn't been posted for a final big round of public review on dri-devel.

In the comments to the article about the AMDGPU feature updates for Linux 4.13, there was nothing said by the AMD developers to indicate they still hoped to get it ready for Linux 4.13, but it was said they are still behind the effort, "Porting the DAL code to the legacy amdgpu modesetting code is probably more work than finishing the DAL rework and you don't get atomic support."

But some "good" news brought to light is that while there won't be any Radeon RX Vega display support until DC lands, it should work with DRI_PRIME. So if you get a Vega GPU and don't want to build your own kernel or rely upon AMDGPU-PRO, but happen to have Intel integrated graphics, you could plug your display into the Intel graphics and activate DRI_PRIME for rendering via Vega... Less than ideal, but at least that works.

Here's hoping that AMDGPU DC will be ready for Linux 4.14 for Vega / Raven Ridge display support, atomic mode-setting, HDMI 2.0, FreeSync, and finally having HDMI/DP audio on modern Radeon GPUs. The sad part though is Ubuntu 17.10 and other September~October distributions will likely be shipping with Linux 4.13.