[x86] drm/i915: do not enable RC6p on Sandy Bridge (Closes: #660265)

svn path=/dists/sid/linux-2.6/; revision=18737

debian/changelog

@@ -22,6 +22,7 @@ linux-2.6 (3.2.7-1) UNRELEASED; urgency=low
   * [i386] Re-enable INTEL_IOMMU, IRQ_REMAP
   * [mips/r5k-ip32] Enable INPUT_SGI_BTNS (previously INPUT_SGIO2_BTNS)
   * [powerpc/powerpc64] Enable IBM_EMAC (previously IBM_NEW_EMAC)
+  * [x86] drm/i915: do not enable RC6p on Sandy Bridge (Closes: #660265)
 
   [ Bastian Blank ]
   * Don't advertise Xen support for rt images. (closes: #659988)

debian/patches/bugfix/x86/drm-i915-do-not-enable-RC6p-on-Sandy-Bridge.patch

@@ -0,0 +1,45 @@
+From: Eugeni Dodonov <eugeni.dodonov@intel.com>
+Date: Tue, 14 Feb 2012 11:44:48 -0200
+Subject: [PATCH] drm/i915: do not enable RC6p on Sandy Bridge
+
+commit 1c8ecf80fdee4e7b23a9e7da7ff9bd59ba2dcf96 upstream.
+
+With base on latest findings, RC6p seems to be respondible for RC6-related
+issues on Sandy Bridge platform. To work-around those issues, the previous
+solution was to completely disable RC6 on Sandy Bridge for the past few
+releases, even if plain RC6 was not giving any issues.
+
+What this patch does is preventing RC6p from being enabled on Sandy Bridge
+even if users enable RC6 via a kernel parameter. So it won't change the
+defaults in any way, but will ensure that if users do enable RC6 manually
+it won't break their machines by enabling this extra state.
+
+Proper fix for this (enabling specific RC6 states according to the GPU
+generation) were proposed for the -next kernel, but we are too late in the
+release process now to pick such changes.
+
+Acked-by: Keith Packard <keithp@keithp.com>
+Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
+Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
+---
+ drivers/gpu/drm/i915/intel_display.c |    4 ++--
+ 1 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
+index d9b042b..049804e 100644
+--- a/drivers/gpu/drm/i915/intel_display.c
++++ b/drivers/gpu/drm/i915/intel_display.c
+@@ -8182,8 +8182,8 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
+ 	I915_WRITE(GEN6_RC6pp_THRESHOLD, 64000); /* unused */
+ 
+ 	if (intel_enable_rc6(dev_priv->dev))
+-		rc6_mask = GEN6_RC_CTL_RC6p_ENABLE |
+-			GEN6_RC_CTL_RC6_ENABLE;
++		rc6_mask = GEN6_RC_CTL_RC6_ENABLE |
++			(IS_GEN7(dev_priv->dev)) ? GEN6_RC_CTL_RC6p_ENABLE : 0;
+ 
+ 	I915_WRITE(GEN6_RC_CONTROL,
+ 		   rc6_mask |
+-- 
+1.7.9.1
+

debian/patches/bugfix/x86/drm-i915-fix-operator-precedence-when-enabling-RC6p.patch

@@ -0,0 +1,30 @@
+From: Eugeni Dodonov <eugeni.dodonov@intel.com>
+Date: Thu, 23 Feb 2012 17:57:06 -0800
+Subject: [PATCH 1/1] drm/i915: fix operator precedence when enabling RC6p
+
+As noticed by Torsten Kaiser, the operator precedence can play tricks with
+us here.
+
+CC: Dave Airlie <airlied at redhat.com>
+CC: Jesse Barnes <jbarnes at virtuousgeek.org>
+Signed-off-by: Eugeni Dodonov <eugeni.dodonov at intel.com>
+---
+ drivers/gpu/drm/i915/intel_display.c |    2 +-
+ 1 files changed, 1 insertions(+), 1 deletions(-)
+
+diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
+index e654f32..4871ba0 100644
+--- a/drivers/gpu/drm/i915/intel_display.c
++++ b/drivers/gpu/drm/i915/intel_display.c
+@@ -8194,7 +8194,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv)
+ 
+ 	if (intel_enable_rc6(dev_priv->dev))
+ 		rc6_mask = GEN6_RC_CTL_RC6_ENABLE |
+-			(IS_GEN7(dev_priv->dev)) ? GEN6_RC_CTL_RC6p_ENABLE : 0;
++			((IS_GEN7(dev_priv->dev)) ? GEN6_RC_CTL_RC6p_ENABLE : 0);
+ 
+ 	I915_WRITE(GEN6_RC_CONTROL,
+ 		   rc6_mask |
+-- 
+1.7.8.4
+

debian/patches/series/base

@@ -78,3 +78,5 @@
 + bugfix/arm/ARM-ixp4xx-mtd-oops.patch
 
 + bugfix/all/builddeb-Don-t-create-files-in-tmp-with-predictable-.patch
++ bugfix/x86/drm-i915-do-not-enable-RC6p-on-Sandy-Bridge.patch
++ bugfix/x86/drm-i915-fix-operator-precedence-when-enabling-RC6p.patch