[Trusty][PULL]: ubuntu/i915 backports

[Timo Aaltonen]

	Hi

Here's a commit to ubuntu/i915 which is a combination of 14 commits
smashed together for sanity:

git://kernel.ubuntu.com/tjaalton/ubuntu-trusty.git i915-bdw

drm/i915/bdw: Remove BDW preproduction W/As until C stepping.
drm/i915: Add the WaCsStallBeforeStateCacheInvalidate:bdw workaround.
drm/i915: Refactor Broadwell PIPE_CONTROL emission into a helper.
drm/i915: Replace hardcoded cacheline size with macro
drm/i915/bdw: Cleanup pre prod workarounds
drm/i915/bdw: Apply workarounds in render ring init function
drm/i915: call lpt_init_clock_gating on BDW too
drm/i915/bdw: Disable idle DOP clock gating
drm/i915/bdw: 3D_CHICKEN3 has write mask bits
drm/i915: add null render states for gen6, gen7 and gen8
- Add new workarounds and remove those that cause issues on production
  HW
- Also makes sure the WA's are applied on GPU reset, suspend & resume
  et al
- fixes various cases when the GPU can get hung

drm/i915: respect the VBT minimum backlight brightness
drm/i915: extract backlight minimum brightness from VBT
drm/i915: shuffle panel code
- fix a bug where changing the panel brightness to lowest value
  actually turns the panel off

drm/i915/bdw: Add 42ms delay for IPS disable
- fix the panel getting confused and corrupt when changing resolutions
  back and forth

doesn't touch anything outside ubuntu/i915

-- 
t