From: Rodrigo Vivi Date: Mon, 4 Aug 2014 18:15:19 +0000 (-0700) Subject: Revert "drm/i915: Enable semaphores on BDW" X-Git-Tag: firefly_0821_release~176^2~3449^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=be71eabebaf9f142612d34d42292b454e984dcb5;p=firefly-linux-kernel-4.4.55.git Revert "drm/i915: Enable semaphores on BDW" This reverts commit 521e62e49a42661a4ee0102644517dbe2f100a23. Although POST_SYNC brought a bit of stability to Semaphores on BDW it didn't solved all issues and some hungs can still occour when semaphores are enabled on BDW. Also some sloweness can be found on some igt tests, althoguth it apparently doesn't affect real workloads. Besides that, no real performance gain was found on our tests with different and even multiple workloads. Let's disable it again for now. At least until we are sure it is safe to re-enable it. Signed-off-by: Rodrigo Vivi Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 6c4b25ce8bb0..ec96f9a9724c 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -481,6 +481,10 @@ bool i915_semaphore_is_enabled(struct drm_device *dev) if (i915.semaphores >= 0) return i915.semaphores; + /* Until we get further testing... */ + if (IS_GEN8(dev)) + return false; + #ifdef CONFIG_INTEL_IOMMU /* Enable semaphores on SNB when IO remapping is off */ if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped)