Pallipadi, Venkatesh wrote: [Fri Aug 26 2005, 08:53:35PM EDT] > > Yes. Looks like "ti->drift = HPET_DRIFT;" is right here. However, I > would > like to double check this with Bob. > > Thanks, > Venki > > >-----Original Message----- > >From: Alex Williamson [mailto:[EMAIL PROTECTED] > >Sent: Thursday, August 25, 2005 8:17 AM > >To: Pallipadi, Venkatesh > >Cc: [EMAIL PROTECTED]; linux-kernel@vger.kernel.org > >Subject: HPET drift question > > > >Hi Venki, > > > > I'm confused by the calculation of the drift value in the hpet > >driver. The specs defines the recommended minimum hardware > >implementation is a frequency drift of 0.05% or 500ppm. However, the > >drift passed in when registering with the time interpolator is: > > > >ti->drift = ti->frequency * HPET_DRIFT / 1000000; > > > >Isn't that absolute number of ticks per second drift? The time > >interpolator defines the drift in parts per million. Shouldn't this > >simply be: > > > >ti->drift = HPET_DRIFT; > > > >The current code seems to greatly penalize any hpet timer with greater > >than a 1MHz frequency. Thanks, > > > > Alex > > > >-- > >Alex Williamson HP Linux & Open Source Lab > > > > Hi Venki:
Alex and I had an earlier IRC discussion where we agreed that HPET_DRIFT should be the value. We were just verifying with you. thanks, bob - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
