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Date:   Tue, 20 Jun 2023 21:49:03 -0700
From:   Eduardo Valentin <evalenti@kernel.org>
To:     "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Eduardo Valentin <evalenti@kernel.org>, eduval@amazon.com,
        linux-pm@vger.kernel.org,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Amit Kucheria <amitk@kernel.org>,
        Zhang Rui <rui.zhang@intel.com>,
        Jonathan Corbet <corbet@lwn.net>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 6/7] ythermal: core: report errors to governors
Message-ID: <ZJKBP3YR63i4otsf@uf8f119305bce5e.ant.amazon.com>
References: <20230519032719.2581689-1-evalenti@kernel.org>
 <20230519032719.2581689-7-evalenti@kernel.org>
 <CAJZ5v0hrddGcoqdT6a0+9t20guW_1cZmbNhP_ZuQTmkCLGSKEA@mail.gmail.com>
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On Tue, Jun 20, 2023 at 07:29:57PM +0200, Rafael J. Wysocki wrote:
> 
> 
> 
> On Fri, May 19, 2023 at 5:27 AM Eduardo Valentin <evalenti@kernel.org> wrote:
> >
> > From: Eduardo Valentin <eduval@amazon.com>
> >
> > Currently the thermal governors are not allowed to
> > react on temperature error events as the thermal core
> > skips the handling and logs an error on kernel buffer.
> > This patch adds the opportunity to report the errors
> > when they happen to governors.
> >
> > Now, if a governor wants to react on temperature read
> > errors, they can implement the .check_error() callback.
> 
> Explaining the use case for this would help a lot.


Yeah I agree. I also did not send the full series and will also add
the governor changes for this in the next patch series.

The use case here is primarily when temperature reads can fail.
Common use case, not limited to though, is an I2C device temperature sensor.
While it can be, in many cases, reliable, it is not always guaranteed to
have a successful temperature read. In fact, it is common to see a sporadic
temperature read failure, followed by successful reads.

This patch series will enhance the core to allow temperature update
error communication to the governor so the governor can have the
opportunity to act upon sensor failure.

-- 
All the best,
Eduardo Valentin