[PATCH AUTOSEL 5.2 31/59] drm/amdgpu: fix error handling in amdgpu_cs_process_fence_dep

[Sasha Levin]

From: Christian König <christian.koe...@amd.com>

[ Upstream commit 67d0859e2758ef992fd32499747ce4b1038a63c0 ]

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.koe...@amd.com>
Reviewed-by: Chunming Zhou <david1.z...@amd.com>
Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 26 ++++++++++++--------------
 1 file 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 2f6239b6be6fe..fe028561dc0e6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -1093,29 +1093,27 @@ 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;
 }
-- 
2.20.1