Re: [PATCH v2] thermal: core: Add trip thresholds for trip crossing detection

From: srinivas pandruvada
Date: Fri Nov 03 2023 - 13:43:44 EST


On Fri, 2023-11-03 at 17:30 +0100, Daniel Lezcano wrote:
> On 03/11/2023 16:42, srinivas pandruvada wrote:
> > On Fri, 2023-11-03 at 15:56 +0100, Rafael J. Wysocki wrote:
> > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > >
> > > The trip crossing detection in handle_thermal_trip() does not
> > > work
> > > correctly in the cases when a trip point is crossed on the way up
> > > and
> > > then the zone temperature stays above its low temperature (that
> > > is,
> > > its
> > > temperature decreased by its hysteresis).  The trip temperature
> > > may
> > > be passed by the zone temperature subsequently in that case, even
> > > multiple times, but that does not count as the trip crossing as
> > > long
> > > as
> > > the zone temperature does not fall below the trip's low
> > > temperature
> > > or,
> > > in other words, until the trip is crossed on the way down.
> >
> > In other words you want to avoid multiple trip UP notifications
> > without
> > a corresponding DOWN notification.
> >
> > This will reduce unnecessary noise to user space. Is this the
> > intention?
>
> Not only reduce noise but give a correct information. Otherwise the
> userspace will have to figure out if there are duplicate events after
> the first event happened. The same happen (less often) when crossing
> the
> trip point the way down.
Correct.
The patch looks good to me.

Thanks,
Srinivas


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