drm/amdgpu: do necessary NULL check

Signed-off-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
index 855d56a..21accbd 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
@@ -101,6 +101,9 @@ int amdgpu_sync_resv(struct amdgpu_device *adev,
        unsigned i;
        int r = 0;
 
+       if (resv == NULL)
+               return -EINVAL;
+
        /* always sync to the exclusive fence */
        f = reservation_object_get_excl(resv);
        fence = f ? to_amdgpu_fence(f) : NULL;
@@ -116,12 +119,12 @@ int amdgpu_sync_resv(struct amdgpu_device *adev,
        for (i = 0; i < flist->shared_count; ++i) {
                f = rcu_dereference_protected(flist->shared[i],
                                              reservation_object_held(resv));
-               fence = to_amdgpu_fence(f);
+               fence = f ? to_amdgpu_fence(f) : NULL;
                if (fence && fence->ring->adev == adev) {
                        if (fence->owner != owner ||
                            fence->owner == AMDGPU_FENCE_OWNER_UNDEFINED)
                                amdgpu_sync_fence(sync, fence);
-               } else {
+               } else if (f) {
                        r = fence_wait(f, true);
                        if (r)
                                break;