From: Nayan Deshmukh <nayan26deshmukh@gmail.com>
Date: Fri, 25 May 2018 10:15:46 +0530
Subject: drm/scheduler: fix a corner case in dependency optimization
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Git-commit: 6201e033d77fae5ed6798d3d122643c2fe3c24dd
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

When checking for a dependency fence for belonging to the same entity
compare it with scheduled as well finished fence. Earlier we were only
comparing it with the scheduled fence.

Signed-off-by: Nayan Deshmukh <nayan26deshmukh@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/scheduler/gpu_scheduler.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/scheduler/gpu_scheduler.c
+++ b/drivers/gpu/drm/scheduler/gpu_scheduler.c
@@ -349,8 +349,13 @@ static bool drm_sched_entity_add_depende
 	struct dma_fence * fence = entity->dependency;
 	struct drm_sched_fence *s_fence;
 
-	if (fence->context == entity->fence_context) {
-		/* We can ignore fences from ourself */
+	if (fence->context == entity->fence_context ||
+            fence->context == entity->fence_context + 1) {
+                /*
+                 * Fence is a scheduled/finished fence from a job
+                 * which belongs to the same entity, we can ignore
+                 * fences from ourself
+                 */
 		dma_fence_put(entity->dependency);
 		return false;
 	}