[PATCH] reservation: wait only with non-zero timeout specified (v3)

[Zhou, Jammy]

Sure. I will send the patches out later.

Regards,
Jammy

-----Original Message-----
From: Maarten Lankhorst [mailto:maarten.lankhorst at canonical.com] 
Sent: Wednesday, January 21, 2015 5:12 PM
To: Zhou, Jammy; Daniel Vetter
Cc: Koenig, Christian; dri-devel; Deucher, Alexander
Subject: Re: [PATCH] reservation: wait only with non-zero timeout specified (v3)

Hey,

Op 14-01-15 om 03:16 schreef Zhou, Jammy:
>>> I think it would be best to leave timeout=0 returning 0. Not handling it differently gives the same semantics as used by fence_wait_time and wait_event_timeout.
>>> Are there really many cases in which you don't know if timeout = 0 before or not?
>> Yeah I think with this it's more important to be consistent with all the other wait_something primitives the kernel exposes.
> Okay. I think we can live with that from driver perspective by handling timeout==0 and timeout>0 differently. 
> But it should still be worth adding some notes for reservation_object_wait_timeout_rcu that  the return value cannot be used to judge if the fences are signaled or not when timeout==0.
>
Oops it looks like I was wrong here..

Looking more closely at wait_event_timeout, ___wait_cond_timeout modifies __ret which makes it explicitly handle timeout = 0 by testing.

If you resend your patch I will ack it, but can you send a patch for fixing fence_wait_timeout too to clear any possible confusion?

~Maarten