From: Daniel Vetter <daniel.vet...@ffwll.ch> [ Upstream commit 57fcd550eb15bce14a7154736379dfd4ed60ae81 ]
Not technically a problem for ttm, but very likely a driver bug and pretty big time confusing for reviewing code. So warn about it, both at cleanup time (so we catch these for sure) and at pin/unpin time (so we know who's the culprit). Reviewed-by: Huang Rui <ray.hu...@amd.com> Reviewed-by: Christian König <christian.koe...@amd.com> Signed-off-by: Daniel Vetter <daniel.vet...@intel.com> Cc: Christian Koenig <christian.koe...@amd.com> Cc: Huang Rui <ray.hu...@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201028113120.3641237-1-daniel.vet...@ffwll.ch Signed-off-by: Sasha Levin <sas...@kernel.org> --- drivers/gpu/drm/ttm/ttm_bo.c | 2 +- include/drm/ttm/ttm_bo_api.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 22073e77fdf9..a76eb2c14e8c 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -514,7 +514,7 @@ static void ttm_bo_release(struct kref *kref) * shrinkers, now that they are queued for * destruction. */ - if (bo->pin_count) { + if (WARN_ON(bo->pin_count)) { bo->pin_count = 0; ttm_bo_del_from_lru(bo); ttm_bo_add_mem_to_lru(bo, &bo->mem); diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 2564e66e67d7..79b9367e0ffd 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -600,6 +600,7 @@ static inline bool ttm_bo_uses_embedded_gem_object(struct ttm_buffer_object *bo) static inline void ttm_bo_pin(struct ttm_buffer_object *bo) { dma_resv_assert_held(bo->base.resv); + WARN_ON_ONCE(!kref_read(&bo->kref)); ++bo->pin_count; } @@ -613,6 +614,7 @@ static inline void ttm_bo_unpin(struct ttm_buffer_object *bo) { dma_resv_assert_held(bo->base.resv); WARN_ON_ONCE(!bo->pin_count); + WARN_ON_ONCE(!kref_read(&bo->kref)); --bo->pin_count; } -- 2.30.1
