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    SubjectRe: [lm-sensors] [PATCH 1/3] hwmon: Driver for SMM665 Six-Channel Active DC Output Controller/Monitor
    On Fri, 18 Jun 2010 12:13:25 -0700, Guenter Roeck wrote:
    > On Fri, 2010-06-18 at 14:10 -0400, Jonathan Cameron wrote:
    > > Another quick query. Are the _min / _max attributes as defined in the
    > > abi meant for alarms? I always thought they were to tell userspace the
    > > limits on measurement?
    > >
    > Good question. I thought it is supposed to refer to alarm limits, but I
    > may be wrong.
    >
    > Browsing through a couple of drivers, it _looks_ like the values are
    > used for alarm limits (eg adm1025 or lm85). Limits are not always set to

    Yes, these are alarms. _min and _max are really misnomers, these should
    have been _low and _high but by the time I realized it, _min and _max
    were already de facto standards and it was too late to change this.

    Documentation/hwmon/sysfs-interface says:

    Usual items are "input" (measured value), "max" (high threshold,
    "min" (low threshold).

    Specific occurrences are then left without details. If you think this
    document can be improved, I welcome patches.

    > useful values, though. This is what my CPU board returns:
    >
    > lm85-i2c-0-2e
    > Adapter: SMBus PIIX4 adapter at 0580
    > V1.5: +1.80 V (min = +0.00 V, max = +3.32 V)
    > VCore: +1.29 V (min = +0.00 V, max = +2.99 V)
    > V3.3: +3.32 V (min = +0.00 V, max = +4.38 V)
    > V5: +5.00 V (min = +0.00 V, max = +6.64 V)
    > V12: +12.12 V (min = +0.00 V, max = +15.94 V)
    >
    > The lm85 datasheet says: "If a voltage input either exceeds the value
    > set in the voltage high limit register or falls below the value set in
    > the voltage low limit register, the corresponding bit will be set
    > automatically by the LM85 in the interrupt status registers (41-42h)."
    >
    > > Either way, one of us has misunderstood so perhaps the documentation needs
    > > to be more specific....
    >
    > Agreed.

    --
    Jean Delvare


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