linux-kernel - Re: [PATCH] regulator: core: Skip balancing of the enabled regulators in regulator

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Message-ID: <20191008120611.GG4382@sirena.co.uk>
Date:   Tue, 8 Oct 2019 13:06:11 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Marek Szyprowski <m.szyprowski@...sung.com>
Cc:     linux-kernel@...r.kernel.org, Dmitry Osipenko <digetx@...il.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        Lucas Stach <l.stach@...gutronix.de>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        linux-samsung-soc@...r.kernel.org
Subject: Re: [PATCH] regulator: core: Skip balancing of the enabled
 regulators in regulator_enable()

On Tue, Oct 08, 2019 at 02:01:15PM +0200, Marek Szyprowski wrote:
> On 08.10.2019 13:50, Mark Brown wrote:

> > This then means that for users that might legitimately enable and
> > disable regulators that need to be constrained are forced to change the
> > voltage when they enable the regualtors in order to have their
> > constraints take effect which seems bad.  I'd rather change the the
> > cpufreq consumers to either not do the enable (since there really should
> > be an always-on constraint this should be redundant, we might need to
> > fix the core to take account of their settings though I think we lost
> > that) or to set the voltage to whatever they need prior to doing their
> > first enable, that seems more robust.

> Well, I'm open for other ways of fixing this issue. Calling enable on 
> always-on regulator imho should not change its rate...

Yes, although there is the whole "don't touch things until a consumer
tells us to" thing going on.  I had expected that this was kicking in
because we weren't paying attention to the constraints of disabled
regulators but I can't see the code implementing that any more so I
guess we removed it at some point (it was always debatable).

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