Atomic Mode-Setting Finally Landing For Wayland's Weston Compositor

Going back about two years has been work towards supporting atomic mode-setting on Weston and we are finally seeing this support land for Wayland's reference compositor.

Daniel Stone of Collabora has been leading this longstanding effort adding atomic mode-setting support for Weston. By using the modern atomic mode-setting interface to the Linux DRM drivers, the operation is much cleaner with testing a desired mode ahead of the actual commit operation, reducing possible flickering in some situations, and also being faster than the traditional mode-setting code-paths. With recent Linux kernel releases, the major DRM/KMS drivers support the atomic mode-setting functionality.

On Monday Daniel sent out the v15 patches for the Weston atomic mode-setting series. Hitting mainline Git today is the start of that work including the actual atomic mode-setting for the DRM compositor back-end, atomic properties, etc. But as of writing it doesn't yet land some of the later patches such as for enabling planes for atomic, supporting GBM modifiers, etc. Presumably the rest of those patches will be landing very soon.