[RFC] attempting to hide 30" monitor in kernel (raw)

[Dave Airlie]

All these are on top of rc3 (also in my drm-mst-hide-monitor branch).

So after talking to Keith and Daniel in Chicago I decided to give
another go at hiding the horror that is 30" 4k dual-panel MST
monitors in the kernel.

Also this hw is not going away, if anything it seems to be getting
worse with Dell promising a 5k monitor, requiring 2 MST ports.

The first two patches aren't really part of this series, I should
probably put them in -fixes anyways. (i.e. ignore them)

So this series, contains the functionality changes required to hide
tiled crtc underneath a master crtc, and to keep track of them
for modeset and pageflipping and cursors (not finished).

It also allows EDID patching to fake the super-mode, along with
hiding the sub-connectors.

Patch 9 is probably the biggest hack here due to lack of atomic
modesetting, and how userspace picks crtcs.

Patch 10 is pageflip so hacky as well, and 11 is just bogus
cursor handling, I just wanted to see the cursor in some form for now.

Mostly I'm looking for some high-level review of the concepts of this
and how much harder it'll make life going forward.

Dave.