Call for testing: drm/i915 update to Linux 3.16

[Francois Tigeot]

Hi,

An update of the drm/i915 gpu driver to Linux 3.16 is almost ready

It is available in this git branch:
http://gitweb.dragonflybsd.org/~ftigeot/dragonfly.git/shortlog/refs/heads/drm_i915_linux_3_16v9
(detailled instructions below)


What you can expect:

* A critical function has been fixed to handle errors which could
  previously cause Xorg crashes.
  
* Much improved support for Broadwell GPUs. They should now be fully
  accelerated.

* Various unrelated bug fixes and performance improvements on all GPU
  generations.


This new driver version is currently known to be broken on some Core 2
machines but it will take time to bisect what change caused the regression.
The only working Core 2 box I have left is a single Core Celeron, which
isn't exactly fast for compiling kernels.

Apart from that, the code should work fine on Ivy-Bridge, Haswell, Broadwell
and hopefully other recent GPUs.


How to test the new branch:

* You must use a recent DragonFly 4.3 (-master) system
* git remote add leaf git://leaf.dragonflybsd.org/~ftigeot/dragonfly.git
* git fetch leaf
* git checkout drm_i915_linux_3_16v9
* make kernel && reboot

Enjoy!

-- 
Francois Tigeot