Here are the (hopefully) final versions of the page flip vs. GPU reset fixes. They survive the i-g-t kms_flip flip-vs-modeset-vs-hang and flip-vs-panning-vs-hang tests, as well as stopping the rings while a fullscreen GL application is running under X. Now that we finish the page flips explicitly, the patches should also work on Gen2-Gen4 hardware, assuming we have otherwise working GPU reset support for them.
