drm/amdgpu: fix error handling in amdgpu_cs_process_fence_dep

We always need to drop the ctx reference and should check
for errors first and then dereference the fence pointer.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 12 insertions, 14 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index e069de8b54e6..4e4094f842e7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -1044,29 +1044,27 @@ static int amdgpu_cs_process_fence_dep(struct amdgpu_cs_parser *p,
                         return r;
                 }
 
-                fence = amdgpu_ctx_get_fence(ctx, entity,
-                                             deps[i].handle);
+                fence = amdgpu_ctx_get_fence(ctx, entity, deps[i].handle);
+                amdgpu_ctx_put(ctx);
+
+                if (IS_ERR(fence))
+                        return PTR_ERR(fence);
+                else if (!fence)
+                        continue;
 
                 if (chunk->chunk_id == AMDGPU_CHUNK_ID_SCHEDULED_DEPENDENCIES) {
-                        struct drm_sched_fence *s_fence = to_drm_sched_fence(fence);
+                        struct drm_sched_fence *s_fence;
                         struct dma_fence *old = fence;
 
+                        s_fence = to_drm_sched_fence(fence);
                         fence = dma_fence_get(&s_fence->scheduled);
                         dma_fence_put(old);
                 }
 
-                if (IS_ERR(fence)) {
-                        r = PTR_ERR(fence);
-                        amdgpu_ctx_put(ctx);
+                r = amdgpu_sync_fence(p->adev, &p->job->sync, fence, true);
+                dma_fence_put(fence);
+                if (r)
                         return r;
-                } else if (fence) {
-                        r = amdgpu_sync_fence(p->adev, &p->job->sync, fence,
-                                        true);
-                        dma_fence_put(fence);
-                        amdgpu_ctx_put(ctx);
-                        if (r)
-                                return r;
-                }
         }
         return 0;
 }