This is a note to let you know that I've just added the patch titled
drm/ttm: make ttm_bo_unpin more defensive
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-ttm-make-ttm_bo_unpin-more-defensive.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7f69522b0d84c4482b44717e8afe2c4f90d26529
Author: Christian König <christian.koenig@xxxxxxx>
Date: Fri Mar 12 09:34:39 2021 +0100
drm/ttm: make ttm_bo_unpin more defensive
[ Upstream commit 6c5403173a13a08ff61dbdafa4c0ed4a9dedbfe0 ]
We seem to have some more driver bugs than thought.
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Fixes: deb0814b43f3 ("drm/ttm: add ttm_bo_pin()/ttm_bo_unpin() v2")
Acked-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210312093810.2202-1-christian.koenig@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 79b9367e0ffd..b5bef3199196 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -613,9 +613,11 @@ 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,
