[Oneirc SRU] SAUCE: Bug#891270 drm/i915: add multi-threaded forcewake support

[manoj.iyer at canonical.com]

From: Manoj Iyer <manoj.iyer at canonical.com>

Please consider the following sauce patch to Oneiric. 

SRU JUSTIFICATION
================

ISSUE
=====
Ivybridge system fails to resume from S3/S4 with recent BIOS. On system resume causes kernel oops in i915 driver.

FIX
===
Upstream fixed the issue by adding multi-threaded forcewake support.
On IVB C0+ with newer BIOSes, the forcewake handshake has changed. There's
now a bitfield for different driver components to keep the GT powered
on. On Linux, we centralize forcewake handling in one place, so we
still just need a single bit, but we need to use the new registers if MT
forcewake is enabled.

TEST
=====
This patch was tested on Ivybridge system with the kernel posted at http://kernel.ubuntu.com/~sarvatt/fdo42923/ and the test results are noted in comment #3 in this bug, and also reported the same to https://bugs.freedesktop.org/show_bug.cgi?id=42923

The following changes since commit f0bba7483b90dabcf025dc923e0722f5ff9b5e6d:

  UBUNTU: SAUCE: drm/i915: add multi-threaded forcewake support (2011-11-21 11:37:20 -0600)

are available in the git repository at:
  git://kernel.ubuntu.com/manjo/ubuntu-oneiric.git lp891270

Manoj Iyer (1):
  UBUNTU: SAUCE: drm/i915: add multi-threaded forcewake support

 drivers/gpu/drm/i915/i915_drv.c      |   30 ++++++++++++++++++++++++++----
 drivers/gpu/drm/i915/i915_drv.h      |    8 ++++++++
 drivers/gpu/drm/i915/i915_reg.h      |    4 ++++
 drivers/gpu/drm/i915/intel_display.c |   22 ++++++++++++++++++++++
 4 files changed, 60 insertions(+), 4 deletions(-)

-- 
1.7.5.4