drm/amdgpu: fix NULL ptr dref in the VM code

The exclusive fence is of course perfectly optional here.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 1e3a36c90d38..75481cf3348f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1789,9 +1789,11 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
                         return r;
 
                 /* Wait for any BO move to be completed */
-                r = dma_fence_wait(exclusive, true);
-                if (unlikely(r))
-                        return r;
+                if (exclusive) {
+                        r = dma_fence_wait(exclusive, true);
+                        if (unlikely(r))
+                                return r;
+                }
 
                 params.func = amdgpu_vm_cpu_set_ptes;
                 params.pages_addr = pages_addr;