Hi Grant,
> Requirements:
Agreed on everything, except:
> automatic fan clock divider
> ````````````````````````````
> * User sets 0 to fan_min limit
> - low speed alarm is disabled
> - fan clock divider not changed
> - auto fan clock adjuster disabled
Why would we want to disable the auto fan clock adjuster in this case?
> * User sets fan_min limit too low
> - low speed alarm is enabled
> - fan clock divider set to max
> - fan_min set to register value 254 which corresponds
> to 664 rpm on adm9240
> - low speed alarm will be asserted if fan speed is
> less than minimum measurable speed
> - auto fan clock adjuster disabled (by virtue fan_div == max)
> * User sets reasonable fan speed
> - low speed alarm is enabled
> - fan clock divider set to suit fan_min
> - auto fan clock adjuster enabled
> * User sets unreasonably high low fan speed limit
> - resolution of the low speed limit may be reduced
> - alarm will be asserted
> - fan speed may be displayed as zero until the auto fan
> clock divider adjuster brings fan speed clock divider
> back into chip measurement range, this will occur
> within a few measurement cycles.
You also missed one case, which is the main reason why the whole thing
is (IMHO) needed:
* User doesn't set any limit
- auto fan clock adjuster enabled
But all in all it looks like we finally agree on what the best strategy
is :)
--
Jean Delvare
