Support for laptop multiplexers
Some laptops have a multiplexer that allows software to switch a display between integrated and dedicated GPUs. This can be used to switch a display from the integrated to the dedicated GPU while doing direct scanout for maximum performance and reduced power draw without sacrificing power draw in all other cases. Later on with some things from #46 implemented we could also expose a direct user controllable switch for this, allowing them to change the used GPU for both compositing and displaying on the fly.
For how to do this switching I know of https://www.kernel.org/doc/html/v4.18/gpu/vga-switcheroo.html, but the exposed sysfs interface doesn't really seem suitable, the interactions with drm aren't really specified and if the switching can be performed while preventing blanking for a modeset etc is also not clear.
As NVidia mentioned this topic in this post, maybe @ekurzinger knows something about it? Is there any existing API we can use?