[3.2.y] drm/i915: add Ivy Bridge GT2 Server entries

[Jonathan Nieder <jrnieder@gmail.com>]

Hi Ben,

Please consider

  cc22a938fc1d drm/i915: add Ivy Bridge GT2 Server entries, 2012-03-29

for application to the 3.2.y tree.  It adds a PCI id to the i915
driver, making kms work.  It was applied during the 3.4-rc2 cycle, so
newer stable kernels don't need it.

Maik Zumstrull tried it[1] on top of 3.2.30 and found it to work ok
(thanks!).

Note that pre-2.4.34 versions of libdrm don't cope well with that
card, with or without this patch:

 - without this patch, modern X errors out instead of starting,
   because the intel driver requires kms.  (In a hypothetical better
   world, userspace would know to fall back to vesa or something.)

 - with this patch and with libdrm patch 2.4.34~22 (intel: add Ivy
   Bridge GT2 server variant, 2012-03-29), X should work great

 - with this patch, without libdrm 2.4.34~22, but with libdrm patch
   2.4.38~10 (intel: Bail gracefully if we encounter an unknown Intel
   device, 2012-07-25) applied, X should error out instead of starting

 - with this patch, and with libdrm lacking 2.4.34~22 and 2.4.38~10,
   X freezes at startup.

"No regressions" means you probably shouldn't take this patch without
a safety to work around the old X userspace, unless you can shout
enough in release notes to get people to apply 2.4.38~10 to libdrm and
maintain sanity. ;)

Hmm?
Jonathan

[1] http://bugs.debian.org/684767