add i915 gpu hang fix

PKGBUILD

@@ -8,7 +8,7 @@ pkgname=('linux' 'linux-headers' 'linux-docs') # Build stock -ARCH kernel
 _kernelname=${pkgname#linux}
 _basekernel=3.2
 pkgver=${_basekernel}
-pkgrel=2
+pkgrel=3
 arch=('i686' 'x86_64')
 url="http://www.kernel.org/"
 license=('GPL2')
@@ -21,13 +21,15 @@ source=("http://www.kernel.org/pub/linux/kernel/v3.x/linux-3.2.tar.xz"
         # standard config files for mkinitcpio ramdisk
         "${pkgname}.preset"
         'change-default-console-loglevel.patch'
-        'i915-fix-ghost-tv-output.patch')
+        'i915-fix-ghost-tv-output.patch'
+        'i915-gpu-finish.patch')
 md5sums=('364066fa18767ec0ae5f4e4abcf9dc51'
-         '4a6567864c49c5bb0f7d76d1a638912e'
+         '4079a2ae3e2ee308e6db188f7bc04959'
-         'd9efdc5f471a4082caf2f61afede6302'
+         '875b121a32a619e0ee262c541f330427'
          'eb14dcfd80c00852ef81ded6e826826a'
          '9d3c56a4b999c8bfbd4018089a62f662'
-         '263725f20c0b9eb9c353040792d644e5')
+         '263725f20c0b9eb9c353040792d644e5'
+         '4cd79aa147825837dc8bc9f6b736c0a0')
 
 build() {
   cd "${srcdir}/linux-${_basekernel}"
@@ -38,6 +40,10 @@ build() {
   # add latest fixes from stable queue, if needed
   # http://git.kernel.org/?p=linux/kernel/git/stable/stable-queue.git
 
+  # fix FS#27883
+  # drm/i915: Only clear the GPU domains upon a successful finish
+  patch -Np1 -i "${srcdir}/i915-gpu-finish.patch"
+
   # Some chips detect a ghost TV output
   # mailing list discussion: http://lists.freedesktop.org/archives/intel-gfx/2011-April/010371.html
   # Arch Linux bug report: FS#19234

i915-gpu-finish.patch

@@ -0,0 +1,55 @@
+commit 389a55581e30607af0fcde6cdb4e54f189cf46cf
+Author: Chris Wilson <chris@chris-wilson.co.uk>
+Date:   Tue Nov 29 15:12:16 2011 +0000
+
+    drm/i915: Only clear the GPU domains upon a successful finish
+    
+    By clearing the GPU read domains before waiting upon the buffer, we run
+    the risk of the wait being interrupted and the domains prematurely
+    cleared. The next time we attempt to wait upon the buffer (after
+    userspace handles the signal), we believe that the buffer is idle and so
+    skip the wait.
+    
+    There are a number of bugs across all generations which show signs of an
+    overly haste reuse of active buffers.
+    
+    Such as:
+    
+      https://bugs.freedesktop.org/show_bug.cgi?id=29046
+      https://bugs.freedesktop.org/show_bug.cgi?id=35863
+      https://bugs.freedesktop.org/show_bug.cgi?id=38952
+      https://bugs.freedesktop.org/show_bug.cgi?id=40282
+      https://bugs.freedesktop.org/show_bug.cgi?id=41098
+      https://bugs.freedesktop.org/show_bug.cgi?id=41102
+      https://bugs.freedesktop.org/show_bug.cgi?id=41284
+      https://bugs.freedesktop.org/show_bug.cgi?id=42141
+    
+    A couple of those pre-date i915_gem_object_finish_gpu(), so may be
+    unrelated (such as a wild write from a userspace command buffer), but
+    this does look like a convincing cause for most of those bugs.
+    
+    Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
+    Cc: stable@kernel.org
+    Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
+    Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
+
+diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
+index d560175..036bc58 100644
+--- a/drivers/gpu/drm/i915/i915_gem.c
++++ b/drivers/gpu/drm/i915/i915_gem.c
+@@ -3087,10 +3087,13 @@ i915_gem_object_finish_gpu(struct drm_i915_gem_object *obj)
+ 			return ret;
+ 	}
+ 
++	ret = i915_gem_object_wait_rendering(obj);
++	if (ret)
++		return ret;
++
+ 	/* Ensure that we invalidate the GPU's caches and TLBs. */
+ 	obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
+-
+-	return i915_gem_object_wait_rendering(obj);
++	return 0;
+ }
+ 
+ /**