[PATCH] dma-buf/fence-array: get signaled state when signaling is disabled

[Christian König]

Dropping the rest of the patch, cause that really doesn't make sense any 
more.

Am 22.09.2016 um 12:40 schrieb Gustavo Padovan:
>> E.g. for example it is illegal to do something like
>> >"while(!fence_is_signaled(f)) sleep();" without enabling signaling before
>> >doing this.
>> >
>> >Could just be a misunderstanding, but the comments on your patch actually
>> >sounds a bit like somebody is trying to do exactly that.
> I think the usecase in mind here is poll(fd, timeout=0)

Exactly as I feared. Even if userspace polls with timeout=0 you still 
need to call enable_signaling().

Otherwise you can run into a situation where userspace only uses 
timeout=0 and so never activates the signaling check in the driver.

This would in turn result in an endless loop on implementations where 
the driver never signals fences on their own.

Regards,
Christian.
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