[PATCH xserver 0/2] Clean up modesetting vblank code. Add new API

[Keith Packard]

Daniel Vetter asked if I might demonstrate the new kernel vblank API
I've proposed by implementing support in the modesetting driver. It
turned out to be a good idea because the easiest way was to wrap
drmWaitVBlank in a new function that provided a simpler API and then
go add support for the new interface there.

The result was that I discovered some of the existing callers were not
handling the kernel event queue being full by checking for EBUSY and
calling ms_flush_drm_events.

So, the first patch fixes real bugs, and cleans up the code to boot.

The second patch adds support for the new kernel interface I've
proposed. The API is supported in my drm library's 'drm-lease' branch
here:

	git://people.freedesktop.org/~keithp/drm.git drm-lease