Messages in this thread | | | Subject | Re: [RFC] maximum latency tracking infrastructure | From | Arjan van de Ven <> | Date | Fri, 25 Aug 2006 10:19:45 +0200 |
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On Thu, 2006-08-24 at 23:24 +0100, Matthew Garrett wrote: > On Thu, Aug 24, 2006 at 07:41:35PM +0200, Arjan van de Ven wrote: > > > + /* the ipw2100 hardware really doesn't want power management delays > > + * longer than 500usec > > + */ > > + modify_acceptable_latency("ipw2100", 500); > > + > > Hm. My BIOS claims that the C3 transition period is 85usec (and even my > C4 is 185) , but I've hit the error path where C3 gets disabled. Is this > really adequate?
first of all that 500 is a bit of a guess on my side; James (the Intel wireless guy) is on holiday so I couldn't get real numbers out of it. But as proof of concept it's pretty ok :)
> Also, by the looks of it, the C3 disabling path is > still present - is it still theoretically necessary with the above, or > is this just a belt and braces approach?
the "problem" is that bioses lie about these numbers all the time as well ;( (it's getting better but still).
Those numbers you gave, were those on batter or on AC ? (apparently for the problem machines C3 latency goes WAY up when on battery, and then the problem hits) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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