[PATCH 1/3] drm/scheduler: fix a corner case in dependency optimization

[Nayan Deshmukh]

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 at gmail.com>
---
 drivers/gpu/drm/scheduler/gpu_scheduler.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/gpu_scheduler.c b/drivers/gpu/drm/scheduler/gpu_scheduler.c
index df1578d6f42e..44d480768dfe 100644
--- 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_dependency_cb(struct drm_sched_entity *entity)
 	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;
 	}
-- 
2.14.3