There were a few potential problems with the original page_flip/vblank
code in mdp4_crtc.
1) We need vblank irq for a couple things, both completing flips and
updating cursor. We need to keep track of what work is pending so
that (for example) a cursor update while we are still waiting for
pageflip_cb (ie. pageflip requested from userspace, but still
waiting for rendering to complete) would not prematurely trigger
event to userspace.
2) A preclose -> pageflip-cancel should not cancel a pageflip that
was requested on a different file (ie. non-master closing should
not cancel a pending pageflip).
With these fixes, we no longer have problems w/ cursor not updating and
with occasional hangs with userspace waiting for a pageflip that had
been cancelled (launching XBMC from gnome-shell overview mode was a good
way to trigger this, but now works reliably).
Signed-off-by: Rob Clark <robdclark@gmail.com>
2a2b8fa628