[PATCH 1/4] dma-buf/fence: make timeout handling in fence_default_wait consistent

Christian König deathsimple at vodafone.de
Tue Oct 25 12:25:08 UTC 2016


From: Christian König <christian.koenig at amd.com>

Kernel functions taking a timeout usually return 1 on success even
when they get a zero timeout.

Signen-off-by: Christian König <christian.koenig at amd.com>
Reviewed-by: Chunming Zhou <david1.zhou at amd.com>
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
---
 drivers/dma-buf/fence.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/fence.c b/drivers/dma-buf/fence.c
index 4d51f9e..fb915ab 100644
--- a/drivers/dma-buf/fence.c
+++ b/drivers/dma-buf/fence.c
@@ -335,18 +335,20 @@ fence_default_wait_cb(struct fence *fence, struct fence_cb *cb)
  * @timeout:	[in]	timeout value in jiffies, or MAX_SCHEDULE_TIMEOUT
  *
  * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or the
- * remaining timeout in jiffies on success.
+ * remaining timeout in jiffies on success. If timeout is zero the value one is
+ * returned if the fence is already signaled for consistency with other
+ * functions taking a jiffies timeout.
  */
 signed long
 fence_default_wait(struct fence *fence, bool intr, signed long timeout)
 {
 	struct default_wait_cb cb;
 	unsigned long flags;
-	signed long ret = timeout;
+	signed long ret = timeout ? timeout : 1;
 	bool was_set;
 
 	if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->flags))
-		return timeout;
+		return ret;
 
 	spin_lock_irqsave(fence->lock, flags);
 
-- 
2.5.0



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