drm/i915: disable rc6 on ilk when vt-d is enabled
It blows up. And hopefully this is the root-cause of the mysterious
rc6 related hang on ilk. For reference, the commit that enabled rc6 on
ilk again is:
commit 456470eb583f063ee84c6818251e638598be0fb8
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Wed Aug 8 23:35:40 2012 +0200
drm/i915: enable rc6 on ilk again
Reported-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index c0721ff..ebe3498 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2372,6 +2372,11 @@
return i915_enable_rc6;
if (INTEL_INFO(dev)->gen == 5) {
+#ifdef CONFIG_INTEL_IOMMU
+ /* Disable rc6 on ilk if VT-d is on. */
+ if (intel_iommu_gfx_mapped)
+ return false;
+#endif
DRM_DEBUG_DRIVER("Ironlake: only RC6 available\n");
return INTEL_RC6_ENABLE;
}