From: Chris Wilson Date: Sat, 10 Nov 2012 10:00:06 +0000 (+0000) Subject: Revert "drm/i915: enable rc6 on ilk again" X-Git-Tag: v3.7-rc8~19^2~2^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6567d748c4e94e3481e523803ec07ebd825c80d6;p=platform%2Fkernel%2Flinux-stable.git Revert "drm/i915: enable rc6 on ilk again" Even with the cumulative set of ilk w/a, rc6 is demonstrably still failing and causing GPU hangs as found by Peter Wu. So we need to disable it again until it is stable. This reverts commit 456470eb583f063ee84c6818251e638598be0fb8 Author: Daniel Vetter Date: Wed Aug 8 23:35:40 2012 +0200 drm/i915: enable rc6 on ilk again and the follow-on commit cd7988eea561a70a4f98e431c1395f913672d626 Author: Daniel Vetter Date: Sun Aug 26 20:33:18 2012 +0200 drm/i915: disable rc6 on ilk when vt-d is enabled Note: The situation around the gen4/5 gpu hangs that cropped up in 3.7 is rather strange. Most useful bisects have lead to commit 6c085a728cf000ac1865d66f8c9b52935558b328 Author: Chris Wilson Date: Mon Aug 20 11:40:46 2012 +0200 drm/i915: Track unbound pages or even later commits that affect the gem bo recycling, which all is way past the point where we re-enabled rc6. But somehow reverting/disabling those commits doesn't help, but disabling rc6 at least helps for many hangs on ilk. Obviously it doesn't change anything at all on gen4, and there are still strange issues left on gen5 (which we unfortunately can't readily reproduce). Also, the error_state signature of the hangs which can be fixed with this patch look remarkably different to those which seem to be unaffected by the rc6 settings: The rc6 hangs are in the ring, somewhere in the MI_FLUSH/PIPE_CONTROL sequence to make ilk coherent, wheras all the other hangs tend to be at a random point in the middle of the user batch. So it could also be that we have different issues. Until we grow more clue, this at least helps some users. Reported-by: Peter Wu References: https://bugs.freedesktop.org/show_bug.cgi?id=55984 Signed-off-by: Chris Wilson [danvet: Added note with some more details about the gen4/5 3.7 gpu hang regression.] Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 72f41aa..442968f 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -2373,15 +2373,9 @@ int intel_enable_rc6(const struct drm_device *dev) if (i915_enable_rc6 >= 0) 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; - } + /* Disable RC6 on Ironlake */ + if (INTEL_INFO(dev)->gen == 5) + return 0; if (IS_HASWELL(dev)) { DRM_DEBUG_DRIVER("Haswell: only RC6 available\n");