updating modesetting driver

[Dave Airlie]

Hi guys,

I've pushed a 'restart' branch to the xf86-video-modesetting driver,

Its a basic attempt to write a simple generic unaccelerated, fallback
driver for KMS. I need this to do some hotplug testing and work.

Features:
argb cursor support
randr 1.2
dirty tracking ioctl support.

Differences from modesetting driver:
drops all dri2/exa knowledge.
uses kernel dumb interface directly for bo create/map
based on mature radeon modesetting code.
probing based on fbdev driver (can be improved).

While working on it I noticed we don't have enough information from
the kernel to do certain things in a generic way:

we don't know the max cursor dimensions or whether the hw supports
argb/monochrome cursors
we don't know the allow set of bpp/depth combinations for
autoconfiguration of every device to work.

Now I could expose these from the kernel, but I get the feeling I'd be
walking into a world of pain with people
requesting an info ioctl exposes all kinds of arcane or insane
depth/bpp combos. I'm thinking of maybe
exposing a preferred depth/bpp and 2 sets of cursor limits (one for
argb, one for mono), in order to get autoconfig
working and userspace can override and try insane things with xorg.conf.

Dave.