Messages in this thread | | | Subject | HPET drift question | From | Alex Williamson <> | Date | Thu, 25 Aug 2005 09:17:08 -0600 |
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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
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