On Tue, Apr 07, 2015 at 11:05:50AM +0200, Lucas Stach wrote:
A pipe is now simply a channel to a single GPU core. If a given core is able to execute 2d, 3d or vg state is a matter of looking at the feature bits for this pipe. Why would we need a full blown DRM device for that? On i.MX6 you have 3 pipes where each of them is capable of executing in exactly one exec state. On Dove you get a single pipe that is able to switch between 2D and 3D exec state. If userspace is aware of that one could even interleave 2D with 3D execution on a single submit.
This is another issue which needs nailing down and clearly specified. :)
In the case of a GPU with multiple execution states, are you intending each command buffer submitted should ensure that the appropriate execution state is selected (via a SET PIPE command) or are you intending the kernel to know about this?