[PATCH] dma-buf: avoid scheduling on fence status query

[Christian König]

Am 26.04.2017 um 11:59 schrieb Dave Airlie:
> On 26 April 2017 at 17:20, Christian König <deathsimple at vodafone.de> wrote:
>> NAK, I'm wondering how often I have to reject that change. We should
>> probably add a comment here.
>>
>> Even with a zero timeout we still need to enable signaling, otherwise some
>> fence will never signal if userspace just polls on them.
>>
>> If a caller is only interested in the fence status without enabling the
>> signaling it should call dma_fence_is_signaled() instead.
> Can we not move the return 0 (with spin unlock) down after we enabling
> signalling, but before
> we enter the schedule_timeout(1)?

Yes, that would be an option.

Christian.

>
> Dave.