drm/amdgpu: WARN once if amdgpu_bo_unpin is called for an unpinned BO

It indicates a pin/unpin imbalance bug somewhere. While the bug isn't
necessarily in the call chain hitting this, it's at least one part
involved.

Reviewed-by: Alex Deucher <[email protected]>
Signed-off-by: Michel Dänzer <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index fd271f9746a29ee6799f623557ffaf0354e31b45..728e15e5d68ac75c8f787896b13cb92a6be99977 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -912,7 +912,7 @@ int amdgpu_bo_unpin(struct amdgpu_bo *bo)
        struct ttm_operation_ctx ctx = { false, false };
        int r, i;
 
-       if (!bo->pin_count) {
+       if (WARN_ON_ONCE(!bo->pin_count)) {
                dev_warn(adev->dev, "%p unpin not necessary\n", bo);
                return 0;
        }