From 9c9b8d63ac5c4c4362d879e7473c4ed0010b7033 Mon Sep 17 00:00:00 2001 From: Rodrigo Vivi Date: Mon, 4 Aug 2014 11:15:19 -0700 Subject: [PATCH] Revert "drm/i915: Enable semaphores on BDW" This reverts commit 95ea3b7c02ad69f7e8ffb6faf3c711087547869e. 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 --- drivers/gpu/drm/i915/i915_drv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 6c4b25ce8bb0b..ec96f9a9724c8 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) -- 2.39.5