This series adds a bunch of scaling and clipping related utility stuff to drm core, and then implementes real clipping for intel sprite planes. Most of this stuff was in my drm_atomic branch already for quite a while, but I did do some minor changes here and there. My glplane test app [1] can now be compiled to use the "legacy" (aka current) drm plane APIs instead of the atomic page flip/modeset APIs. Without the atomic page flip support the test is rather slow due the synchronous vblank waits, and it's also rather ugly (naturally since atomic page flips are needed to compose pretty pictures). But anyways, since the test can throw the plane around and off the screen in various ways, I think it's a decent test case for this code. [1] https://gitorious.org/vsyrjala/glplane
