AMDGPU Linux 4.21 Changes Queued With FreeSync, DC ABM, KFD Compute For Vega12/Polaris12

On Friday AMD's Alex Deucher sent in the latest batch of feature to work DRM-Next ahead of the Linux 4.21 cycle. This mostly included AMDGPU/AMDKFD driver updates but also a lone Radeon DRM driver fix to avoid a possible 32-bit overflow and also DRM scheduler and TTM memory management fixes.

The highlights of this latest batch of AMDGPU Direct Rendering Manager feature work for Linux 4.21 includes:

- The long-awaited FreeSync support as well as Adaptive-Sync. As outlined in that article this week, the kernel bits will finally be in place with Linux 4.21 and the Mesa side changes should also be landing for Mesa 19.0. This long-awaited feature is finally ready for open-source mainline!

- Adaptive Backlight Management (ABM) support within the AMDGPU display code. Currently this is primarily for Raven Ridge laptops. Separately the driver is also now using ACPI for querying the backlight range on supported platforms.

- Kernel Fusion Driver (KFD) support for Polaris 12 and Vega 12 graphics processors. This will allow the ROCm compute support to work for these parts.

- SDMA paging queue support for Vega GPUs.

There are also various other fixes and clean-ups as outlined via the pull request. This latest feature pull is on top of earlier 4.21 DRM-Next material.

Notably absent is no fixes yet for the broken Radeon RX 590 support.