[PATCH 1/3] dma-buf/fence: make timeout handling in fence_default_wait consistent

[zhoucm1]

On 2016年10月17日 21:55, Christian König wrote:
> 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>

The series is Reviewed-by: Chunming Zhou <david1.zhou 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);
>