[Cooker] randr 1.2 (display switching for Intel graphics chipsets)

[Adam Williamson]

I don't know how many other people this applies to, but I have a laptop
with an external display. The laptop display is a 12", 1280x800 one. The
external monitor is a 20", 1680x1050 one. The laptop has an Intel
graphics chipset. With current stable X stuff, you can't switch between
the internal and external display at the correct resolution without
restarting X: it's just not capable of correctly detecting and switching
between the supported resolutions.

The X folks are working on a new version of xrandr, 1.2, which basically
makes it a hell of a lot better at this sort of stuff: it can detect, on
the fly, exactly what displays are connected and what resolutions
they're capable of. This requires driver modifications, and the Intel
driver is the testbed for these - it's getting all the necessary changes
first, and once everything's worked out there, it'll be ported to other
drivers.

I've known about this stuff for a long time, but it's very bleeding edge
and all done in git branches and I wasn't able to get it all built and
working together. However, Ross Burton (a GNOME hacker who's far smarter
than me) got it all figured out in a blog post:

http://www.burtonini.com/blog/computers/randr-2007-02-06-17-50

I tried to just build the stuff from source but it wouldn't come
together (missing some X server patches necessary for MDV, I think). So
I decided to try updating the Cooker RPMs with the necessary code
instead, and to my shock and amazement, it all works fine on my first
try. I can now switch between my two displays at will with no restarting
X or futzing about required, just a simple xrandr command.

This stuff isn't really ready for general consumption: there's still no
stable release of most of it, and I don't believe xrandr 1.2 will
actually work at all on any video driver but the Intel one. So I have no
intention of putting this stuff in Cooker. However, I will happily
provide my RPMs for anyone running a laptop with the appropriate
hardware who's interested in taking a look. I used the modesetting
branch of the Intel driver, which in addition to xrandr support bypasses
the video BIOS entirely in detecting available video modes, removing the
need to use 915resolution - all the correct modes will be available
without any messing around.

If anyone's interested in this stuff, get in touch with me on IRC or
email or whatever.

This is the first time I've actually done any RPM packaging stuff, btw,
so obviously there's absolutely no guarantees that it won't blow up in
your face. But it works here.
-- 
adamw