linux-kernel - Re: [PATCH 1/4] regulator: core: If consumers don't call regulator_set

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Message-ID: <20180815105728.GW2414@sirena.org.uk>
Date:   Wed, 15 Aug 2018 11:57:29 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Douglas Anderson <dianders@...omium.org>
Cc:     linux-arm-msm@...r.kernel.org, bjorn.andersson@...aro.org,
        collinsd@...eaurora.org, swboyd@...omium.org,
        Liam Girdwood <lgirdwood@...il.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/4] regulator: core: If consumers don't call
 regulator_set_load() assume max

On Tue, Aug 14, 2018 at 10:06:14AM -0700, Douglas Anderson wrote:
> Not all regulator consumers call regulator_set_load().  On some
> regulators (like on RPMh-regulator) this could be bad since the
> regulator framework will treat this as if consumer needs no load.
> It's much better to assume that a dumb client needs the maximum
> possible load so we get correctness first.

If you take this to its logical conclusion we should never have runtime
mode setting - there may be passive components in the system which don't
appear in DT but do affect the load.  It's why we require the machines
to explicitlly enable any changes that the framework does, if we don't
do this then things aren't safe.  You may also have a situation where
some of the drivers that are registered are included in a fixed load
specified by the machine integration.

Dynamic mode setting is just a very hard feature to use usefully,
there's a reason why few systems do it.

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