diff options
Diffstat (limited to 'drivers/dma-buf/dma-resv.c')
| -rw-r--r-- | drivers/dma-buf/dma-resv.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index eb8b733065b2..b1ef4546346d 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -186,6 +186,13 @@ int dma_resv_reserve_fences(struct dma_resv *obj, unsigned int num_fences) dma_resv_assert_held(obj); + /* Driver and component code should never call this function with + * num_fences=0. If they do it usually points to bugs when calculating + * the number of needed fences dynamically. + */ + if (WARN_ON(!num_fences)) + return -EINVAL; + old = dma_resv_fences_list(obj); if (old && old->max_fences) { if ((old->num_fences + num_fences) <= old->max_fences) @@ -313,8 +320,9 @@ void dma_resv_add_fence(struct dma_resv *obj, struct dma_fence *fence, count++; dma_resv_list_set(fobj, i, fence, usage); - /* pointer update must be visible before we extend the num_fences */ - smp_store_mb(fobj->num_fences, count); + /* fence update must be visible before we extend the num_fences */ + smp_wmb(); + fobj->num_fences = count; } EXPORT_SYMBOL(dma_resv_add_fence); @@ -405,7 +413,7 @@ static void dma_resv_iter_walk_unlocked(struct dma_resv_iter *cursor) * * Beware that the iterator can be restarted. Code which accumulates statistics * or similar needs to check for this with dma_resv_iter_is_restarted(). For - * this reason prefer the locked dma_resv_iter_first() whenver possible. + * this reason prefer the locked dma_resv_iter_first() whenever possible. * * Returns the first fence from an unlocked dma_resv obj. */ @@ -428,7 +436,7 @@ EXPORT_SYMBOL(dma_resv_iter_first_unlocked); * * Beware that the iterator can be restarted. Code which accumulates statistics * or similar needs to check for this with dma_resv_iter_is_restarted(). For - * this reason prefer the locked dma_resv_iter_next() whenver possible. + * this reason prefer the locked dma_resv_iter_next() whenever possible. * * Returns the next fence from an unlocked dma_resv obj. */ |