Hi Jean, On Wed, 2010-10-06 at 12:07 -0400, Jean Delvare wrote: > Hi Guenter, [ ... ] > Why not just: > > for (i = 0, update_interval = LM90_MAX_CONVRATE_MS; > i < data->max_convrate; > i++, update_interval >>= 1) > if (interval >= update_interval * 3 / 4) > break; > > The result is the same as far as I can see, and you avoid an arbitrary > constant. > > Note that your algorithm always rounds interval down, even when the > closest integer would be up. Proper rounding would need a different > algorithm to avoid accumulating rounding errors, I think. > > As it stands, requesting a 21 ms update interval will lead to a 31.250 > ms update interval (register value 0x9), reported as 31 ms through > sysfs, while it should preferably lead to a 15.625 ms update interval > (register value 0xa), currently reported as 15 ms but ideally reported > as 16 ms: this is a 7.375 ms error instead of a 8.250 ms error. You may > decide this is unimportant though, I leave it up to you. > Found a simple solution: Shift interval and update_interval to the left by three bits. That avoids the rounding error. Guenter _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
