AMDGPU DC Code Improvements Bring Better Page-Flipping

The once notorious AMDGPU "DC" code (formerly known as DAL) saw a fresh round of patches on Tuesday further improving this display stack shared between the Windows and Linux drivers for advanced functionality from FreeSync to HDMI/DP audio and much more.

With this latest round of AMDGPU DC patches, improving the page-flipping process was a motivation. This new work resulted in the introduction of a DC VM interface to allow virtual memory to be used for flipping to surfaces that are not contiguously allocated. This DC VM interface will allow for better memory efficiency and security.

Also as part of this series, the page-flipping logic improved as up to now it "was against DRM intention and only worked by sheer luck." And also as part of the patches is multi-plane flipping that also helps out the new FreeSync support.

There are 20 patches in total that also offer other fixes as well as round Adaptive Backlight Management (ABM) and CRC capture. These DC improvements will end up being merged for the Linux 5.1 kernel cycle, not the current 5.0 code-base.