On Wed, 5 Nov 2008 11:52:54 -0800 (PST), shaul Karl wrote: > I suggest the following: > > --- sensors3.conf 2008-11-02 19:06:45.000000000 +0200 > +++ sensors3.conf 2008-11-05 21:49:27.000000000 +0200 > @@ -192,7 +192,19 @@ > # > # Think of tempx_max as 'alarm set' and tempx_max_hyst as 'alarm clear' > # thresholds. In most cases the 'max' value should be higher than > -# the 'max_hyst' value by several degrees. > +# the 'max_hyst' value by several degrees. Obviously, having them equal > +# disable the hysteresis mechanism. Many chips will not accept the > +# 'max_hyst' value higher than the 'max' value because internally they > +# store the hysteresis as a delta to the max limit. Other chips will > +# behave in this case as if max_hyst == max, and some may even misbehave, > +# clearing the alarm even though the measurement is above the max limit. > +# There's one exception though: some chips out there disable the > +# hysteresis mechanism or even change the interrupt behavior or even > +# change the interrupt behavior when the hysteresis is set to special > +# value 127. Unfortunately, there is no way for the drivers to expose > +# this property to user-space, so you have to know how if your chip > +# does that. Once again, the bottom line is that the 'max' value should > +# be higher than the 'max_hyst' value by several degrees. > # > # All the set statements from this file are commented out by default. > # The reason is that the proper limits are highly system-dependent, I don't think it makes a lot of sense to document with that many details something the user shouldn't do in the first place (tempx_max_hyst greater than tempx_max), or an unspecified, chip-specific behavior (special value 127) nor to repeat the same thing twice a dozen lines apart (the 'max' value should be higher than the 'max_hyst' value by several degrees.) So the only added value here is: "Obviously, having them equal disable the hysteresis mechanism." I'll add this now. That being said, I still believe that all this documentation should be moved from sensors.conf.eg to sensors.conf.5. Well apparently the manual page was originally a copy of the header comment of sensors.conf.eg, but they have diverged now. It's no good to have to maintain documentation twice. -- Jean Delvare
