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Message-ID: <575f0538-1963-59fa-582f-6686f67b2f29@linaro.org>
Date:   Tue, 13 Jun 2023 09:00:24 +0200
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Subject: Re: [PATCH] thermal: Allow selecting the bang-bang governor as
 default
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To:     Thierry Reding <thierry.reding@gmail.com>,
        "Rafael J . Wysocki" <rafael@kernel.org>
Cc:     Amit Kucheria <amitk@kernel.org>, Zhang Rui <rui.zhang@intel.com>,
        linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230609124408.3788680-1-thierry.reding@gmail.com>
From:   Daniel Lezcano <daniel.lezcano@linaro.org>
In-Reply-To: <20230609124408.3788680-1-thierry.reding@gmail.com>
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On 09/06/2023 14:44, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> For many setups the bang-bang governor is exactly what we want. Many
> ARM SoC-based devices use fans to cool down the entire SoC and that
> works well only with the bang-bang governor because it uses the
> hysteresis in order to let the fan run for a while to cool the SoC
> down below the trip point before switching it off again.
> 
> The step-wise governor will behave strangely in these situations. It
> doesn't use the hysteresis, so it can lead to situations where the fan
> is turned on for only a very brief period and then is switched back off,
> only to get switched back on again very quickly because the SoC hasn't
> cooled down very much.

Applied, thanks

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