[PATCH 05/17] drm/ttm: call ttm_bo_wait while inside a reservation

Maarten Lankhorst
2014-07-09T12:29:38Z

This is the last remaining function that doesn't use the reservation
lock completely to fence off access to a buffer.
---
drivers/gpu/drm/ttm/ttm_bo.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 4ab9f7171c4f..d7d34336f108 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -502,17 +502,6 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
if (ret)
return ret;

- /*
- * remove sync_obj with ttm_bo_wait, the wait should be
- * finished, and no new wait object should have been added.
- */
- spin_lock(&bdev->fence_lock);
- ret = ttm_bo_wait(bo, false, false, true);
- WARN_ON(ret);
- spin_unlock(&bdev->fence_lock);
- if (ret)
- return ret;
-
spin_lock(&glob->lru_lock);
ret = __ttm_bo_reserve(bo, false, true, false, 0);

@@ -528,8 +517,16 @@ static int ttm_bo_cleanup_refs_and_unlock(struct ttm_buffer_object *bo,
spin_unlock(&glob->lru_lock);
return 0;
}
- } else
- spin_unlock(&bdev->fence_lock);
+
+ /*
+ * remove sync_obj with ttm_bo_wait, the wait should be
+ * finished, and no new wait object should have been added.
+ */
+ spin_lock(&bdev->fence_lock);
+ ret = ttm_bo_wait(bo, false, false, true);
+ WARN_ON(ret);
+ }
+ spin_unlock(&bdev->fence_lock);

if (ret || unlikely(list_empty(&bo->ddestroy))) {
__ttm_bo_unreserve(bo);
@@ -1539,6 +1536,8 @@ int ttm_bo_wait(struct ttm_buffer_object *bo,
void *sync_obj;
int ret = 0;

+ lockdep_assert_held(&bo->resv->lock.base);
+
if (likely(bo->sync_obj == NULL))
return 0;