Re: [PATCH v3 3/4] hwmon: (adt7475) temperature smoothing

[Guenter Roeck]

On 05/14/2017 02:23 PM, Chris Packham wrote:
> On 15/05/17 03:40, Guenter Roeck wrote:
> > On 05/10/2017 08:45 PM, Chris Packham wrote:
> > > When enabled temperature smoothing allows ramping the fan speed over a
> > > configurable period of time instead of jumping to the new speed
> > > instantaneously.
> > >
> > > Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> > > ---
> > >
> > > Changes in v2:
> > > - use a single tempN_smoothing attribute
> >
> > This is a bit confusing. tempN suggests that the attribute would be associated
> > with a given temperature, not with fan control. Not that I have a better idea
> > for an attribute name, though, so unless you find a better name I am ok with it.
>
> The datasheet is a bit confusing in this respect.
>
>  From the description of register 0x62:
>
> "Assuming that PWMx is associated with the Remote 1 temperature channel,
> these bits define the maximum rate of change of the PWMx output for
> Remote 1 temperature related changes. Instead of the fan speed jumping
> instantaneously to its newly determined speed, it ramps
> gracefully at the rate determined by these bits. This feature ultimately
> enhances the acoustics of the fan."
>
> Based on my reading it's a property of the temperature input not of the
> PWM. If you changed pwmN_auto_channels_temp this setting would stay with
> the temperature sensor not the PWM.

Agreed, that is why I said that I don't have a better idea ...

Guenter