2017-11-21 14:28:21

by Christian König

[permalink] [raw]
Subject: Re: [PATCH] reservation: don't wait when timeout=0

Am 21.11.2017 um 15:08 schrieb Rob Clark:
> If we are testing if a reservation object's fences have been
> signaled with timeout=0 (non-blocking), we need to pass 0 for
> timeout to dma_fence_wait_timeout().
>
> Plus bonus spelling correction.
>
> Signed-off-by: Rob Clark <[email protected]>

Reviewed-by: Christian König <[email protected]>

> ---
> drivers/dma-buf/reservation.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
> index dec3a815455d..71f51140a9ad 100644
> --- a/drivers/dma-buf/reservation.c
> +++ b/drivers/dma-buf/reservation.c
> @@ -420,7 +420,7 @@ EXPORT_SYMBOL_GPL(reservation_object_get_fences_rcu);
> *
> * RETURNS
> * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
> - * greater than zer on success.
> + * greater than zero on success.
> */
> long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
> bool wait_all, bool intr,
> @@ -483,7 +483,14 @@ long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
> goto retry;
> }
>
> - ret = dma_fence_wait_timeout(fence, intr, ret);
> + /*
> + * Note that dma_fence_wait_timeout() will return 1 if
> + * the fence is already signaled, so in the wait_all
> + * case when we go through the retry loop again, ret
> + * will be greater than 0 and we don't want this to
> + * cause _wait_timeout() to block
> + */
> + ret = dma_fence_wait_timeout(fence, intr, timeout ? ret : 0);
> dma_fence_put(fence);
> if (ret > 0 && wait_all && (i + 1 < shared_count))
> goto retry;



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