[openib-general] Static Rate Questions

[Roland Dreier]

    Dror> - In struct ib_ah_attr, static_rate is defined as u8. What
    Dror> are the expected values that static_rate is supposed to take
    Dror> ? Is it absolute Gb/s ? Gb/s in 2.5Gb/s units ? or relative
    Dror> rate to port speed ?

My understanding is that it is the inter-packet delay.  However I
don't have any strong objection to changing this interface.

    Dror> - In mthca, there are two places setting up the
    Dror> static_rate. One for AH which looks fine. The other one for
    Dror> QP which I believe has a bug.

Yes, you're right.  I'm not sure where the " << 3" came from; I've
deleted it.
	
    Dror> - A question for next generation HW. Would you find it more
    Dror> useful that the HCA supports static rate as an absolute
    Dror> speed (Gb/s) or as a relative ratio to the current port
    Dror> speed ?

I'm not sure it makes much difference one way or the other.  We're not
talking about a lot of complex code to deal with static rates,
whatever the hardware interface is.

 - R.