From 6c5403173a13a08ff61dbdafa4c0ed4a9dedbfe0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20K=C3=B6nig?= Date: Fri, 12 Mar 2021 09:34:39 +0100 Subject: [PATCH] drm/ttm: make ttm_bo_unpin more defensive MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We seem to have some more driver bugs than thought. Signed-off-by: Christian König Fixes: deb0814b43f3 ("drm/ttm: add ttm_bo_pin()/ttm_bo_unpin() v2") Acked-by: Matthew Auld Link: https://patchwork.freedesktop.org/patch/msgid/20210312093810.2202-1-christian.koenig@amd.com --- include/drm/ttm/ttm_bo_api.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index e17be324d95f..b8ca13664fa2 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -612,9 +612,11 @@ static inline void ttm_bo_pin(struct ttm_buffer_object *bo) 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; + if (bo->pin_count) + --bo->pin_count; + else + WARN_ON_ONCE(true); } int ttm_mem_evict_first(struct ttm_bo_device *bdev,