[Nouveau] [PATCH 09/17] drm/radeon: use common fence implementation for fences

[Maarten Lankhorst]

op 22-07-14 16:24, Christian König schreef:
>> No, you really shouldn't be doing much in the check anyway, it's meant to be a lightweight check. If you're not ready yet because of a lockup simply return not signaled yet.
> It's not only the lockup case from radeon I have in mind here. For userspace queues it might be necessary to call copy_from_user to figure out if a fence is signaled or not.
>
> Returning false all the time is probably not a good idea either.
Having userspace implement a fence sounds like an awful idea, why would you want to do that?

A fence could be exported to userspace, but that would only mean it can wait for it to be signaled with an interface like poll..

~Maarten