Re: [PATCH net-next 3/3] dpll: zl3073x: add hwmon support for input reference frequencies

[Ivan Vecera]

On 3/24/26 10:36 PM, Jakub Kicinski wrote:
> On Tue, 24 Mar 2026 13:59:19 +0100 Ivan Vecera wrote:
> > > > In the hardware monitoring world one would have min/max attributes and
> > > > one or more alarm attributes. I never heard about the idea of reporting
> > > > deviations, and for typical hardware monitoring attributes it does not
> > > > really make sense. What would be a "deviation" of a temperature/
> > > > voltage/current/power/humidity sensor ? Such attributes typically have
> > > > an operational range, and they are allowed and even expected to
> > > > fluctuate within that range.
> > >
> > > Ivan, my take on all the above is that using the HWmon interface here is
> > > stretching it too much. I think it would be better to move debugfs
> > > and/or netlink events.
> >
> > I'd rather avoid debugfs... My proposal is to expose absolute measured
> > frequency attribute of dpll-pin and follow phase-offset-monitor
> > functionality:
> >
> > So:
> > * add real-frequency attribute to dpll pin
> > * add real-frequency-monitor attribute dpll device
> > * user will be able to enable/disable monitoring by enabling/disabling
> >     real-frequency-monitor feature (similarly to phase-offset-monitor)
> >
> > Thoughts?
>
> I don't have a strong opinion. IDK where to draw the line between DPLL
> and "random functionality some devices may have". We have 3 DPLL
> maintainers, let's see what their majority opinion is..

I think that line has already been crossed by temperature reporting,
which has been there since the beginning. Actual frequency measurement
is, in my opinion, much closer to the DPLL world than temperature 
reporting. :-)

Anyway, I have the relevant patch-set already prepared, so I can submit
it if you want to see it.

Thanks,
Ivan