[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.koe...@amd.com>
Signed-off-by: Prike Liang <prike.li...@amd.com>
Acked-by: Alex Deucher <alexander.deuc...@amd.com>
Reviewed-by: Arvind Yadav <arvind.ya...@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