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Message-ID: <1cf3bf9cb37ddcf0022f680c3f7f4442c6218c10.camel@linux.intel.com>
Subject: Re: [PATCH v2] thermal: core: Add trip thresholds for trip crossing
 detection
From:   srinivas pandruvada <srinivas.pandruvada@linux.intel.com>
To:     Daniel Lezcano <daniel.lezcano@linaro.org>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Linux PM <linux-pm@vger.kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        Lukasz Luba <lukasz.luba@arm.com>
Date:   Fri, 03 Nov 2023 13:43:33 -0400
In-Reply-To: <3fe787bc-f85c-4268-833f-86922415c4d3@linaro.org>
References: <12317335.O9o76ZdvQC@kreacher>
         <6b22f4715641bc4ffc76eea8a4e6358bcbea9e1c.camel@linux.intel.com>
         <3fe787bc-f85c-4268-833f-86922415c4d3@linaro.org>
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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@intel.com>
> > >=20
> > > 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).=C2=A0 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.
> >=20
> > In other words you want to avoid multiple trip UP notifications
> > without
> > a corresponding DOWN notification.
> >=20
> > This will reduce unnecessary noise to user space. Is this the
> > intention?
>=20
> Not only reduce noise but give a correct information. Otherwise the=20
> userspace will have to figure out if there are duplicate events after
> the first event happened. The same happen (less often) when crossing
> the=20
> trip point the way down.
Correct.
The patch looks good to me.

Thanks,
Srinivas


>=20
>=20
>=20