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| author |   Christian König <christian.koenig@amd.com> | 2019-08-05 11:14:27 +0200 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2019-08-07 12:39:52 +0200 |
| commit | 93505ee7d05e836fd18894019e93c3875198fcc5 (patch) | |
| tree | 897d789bc045b7aa0d249be051cace480cfcba70 /drivers/dma-buf | |
| parent | drm/crc-debugfs: Add notes about CRC<->commit interactions (diff) | |
| download | linux-dev-93505ee7d05e836fd18894019e93c3875198fcc5.tar.xz linux-dev-93505ee7d05e836fd18894019e93c3875198fcc5.zip | |
dma-buf: fix busy wait for new shared fences
When reservation_object_add_shared_fence is replacing an old fence with a new
one we should not drop the old one before the new one is in place.
Otherwise other cores can busy wait for the new one to appear.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/322030/
Diffstat (limited to 'drivers/dma-buf')
| -rw-r--r-- | drivers/dma-buf/reservation.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c index c71b85c8c159..d59207ca72d2 100644 --- a/drivers/dma-buf/reservation.c +++ b/drivers/dma-buf/reservation.c @@ -196,6 +196,7 @@ void reservation_object_add_shared_fence(struct reservation_object *obj, struct dma_fence *fence) { struct reservation_object_list *fobj; + struct dma_fence *old; unsigned int i, count; dma_fence_get(fence); @@ -209,18 +210,16 @@ void reservation_object_add_shared_fence(struct reservation_object *obj, write_seqcount_begin(&obj->seq); for (i = 0; i < count; ++i) { - struct dma_fence *old_fence; - old_fence = rcu_dereference_protected(fobj->shared[i], - reservation_object_held(obj)); - if (old_fence->context == fence->context || - dma_fence_is_signaled(old_fence)) { - dma_fence_put(old_fence); + old = rcu_dereference_protected(fobj->shared[i], + reservation_object_held(obj)); + if (old->context == fence->context || + dma_fence_is_signaled(old)) goto replace; - } } BUG_ON(fobj->shared_count >= fobj->shared_max); + old = NULL; count++; replace: @@ -230,6 +229,7 @@ replace: write_seqcount_end(&obj->seq); preempt_enable(); + dma_fence_put(old); } EXPORT_SYMBOL(reservation_object_add_shared_fence); |