[PATCH v3] drm/amdgpu: lock the eviction fence for wq signals it

[Prike Liang]

Lock and refer to the eviction fence before the eviction fence
schedules work queue tries to signal it.

Suggested-by: Christian König <christian.koenig at amd.com>
Signed-off-by: Prike Liang <Prike.Liang at amd.com>
Acked-by: Alex Deucher <alexander.deucher at amd.com>
Reviewed-by: Arvind Yadav <Arvind.Yadav at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
index 1a7469543db5..5b5d45534d79 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c
@@ -108,13 +108,22 @@ amdgpu_eviction_fence_suspend_worker(struct work_struct *work)
 	struct amdgpu_eviction_fence *ev_fence;
 
 	mutex_lock(&uq_mgr->userq_mutex);
+	spin_lock(&evf_mgr->ev_fence_lock);
 	ev_fence = evf_mgr->ev_fence;
-	if (!ev_fence)
+	if (ev_fence)
+		dma_fence_get(&ev_fence->base);
+	else
 		goto unlock;
+	spin_unlock(&evf_mgr->ev_fence_lock);
 
 	amdgpu_userq_evict(uq_mgr, ev_fence);
 
+	mutex_unlock(&uq_mgr->userq_mutex);
+	dma_fence_put(&ev_fence->base);
+	return;
+
 unlock:
+	spin_unlock(&evf_mgr->ev_fence_lock);
 	mutex_unlock(&uq_mgr->userq_mutex);
 }
 
-- 
2.34.1