[PATCH 29/31] dma-fence: Always execute signal callbacks

Chris Wilson chris at chris-wilson.co.uk
Tue Jul 16 20:12:12 UTC 2019


Allow for some users to surreptiously insert lazy signal callbacks that
do not depend on enabling the signaling mechanism around every fence.
This means that we may have a cb_list even if the signaling bit is not
enabled, so always notify the callbacks.

The cost is that dma_fence_signal() must always acquire the spinlock to
ensure that the cb_list is flushed.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/dma-buf/dma-fence.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index 027a6a894abd..ab4a456bba04 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -170,11 +170,9 @@ int dma_fence_signal(struct dma_fence *fence)
 
 	__dma_fence_signal__timestamp(fence, ktime_get());
 
-	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags)) {
-		spin_lock_irqsave(fence->lock, flags);
-		__dma_fence_signal__notify(fence);
-		spin_unlock_irqrestore(fence->lock, flags);
-	}
+	spin_lock_irqsave(fence->lock, flags);
+	__dma_fence_signal__notify(fence);
+	spin_unlock_irqrestore(fence->lock, flags);
 	return 0;
 }
 EXPORT_SYMBOL(dma_fence_signal);
-- 
2.22.0



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