AMD Developer Posts X.Org Modesetting "MS_ALL_IN_ONE" Patches

Qiang Yu of AMD has been baking a new feature for the xf86-video-modesetting DDX: MS_ALL_IN_ONE.

MS_ALL_IN_ONE is for helping out multi-GPU systems where one DRM device might just be used for the actual display while another GPU without access to the display would do the rendering work for xf86-video-modesetting.

Qiang Yu explained, "start xserver with MS_ALL_IN_ONE=1, and configure both the display (Screen) and render (GPUScreen) drm devices using modesetting DDX, it will use Screen as display, GPUScreen as render and create only one screen. Client see only the render device and load render device's DRI driver. Server side render is also accelerated by the render device. Display device only display what render device draws...Tested on a laptop with Intel iGPU and AMD dGPU."

But a shortcoming of MS_ALL_IN_ONE is that DRI3 page-flipping doesn't work and a further improvement is for supporting multiple display DRM devices. More details via this patch series.