vc4: Enable scanout from T-tiled images. #83
Description
We'll need to define a new vendor-specific tiling modifier in drm_fourcc.h, and recognize that in our plane setup to set the HVS's decode bits.
Apparently this come at a cost in bandwidth during scanout (unknown how bad it is), but would mean that Mesa could always produce T-tiled images, which would be cheaper for copy-based glXSwapBuffers() (windowed mode without a compositor) and for texturing from the framebuffer (X window movement without a compositor)