linux-kernel - Re: [PATCH] regulator: do not balance 'boot-on' coupled regulators without constraints

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Message-ID: <20200605102018.GA5413@sirena.org.uk>
Date:   Fri, 5 Jun 2020 11:20:18 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Marek Szyprowski <m.szyprowski@...sung.com>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...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>,
        Viresh Kumar <viresh.kumar@...aro.org>, peron.clem@...il.com,
        Nishanth Menon <nm@...com>, Stephen Boyd <sboyd@...nel.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Rafael Wysocki <rjw@...ysocki.net>,
        linux-samsung-soc@...r.kernel.org,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Saravana Kannan <saravanak@...gle.com>
Subject: Re: [PATCH] regulator: do not balance 'boot-on' coupled regulators
 without constraints

On Fri, Jun 05, 2020 at 08:37:24AM +0200, Marek Szyprowski wrote:

> Balancing of the 'boot-on' coupled regulators must wait until the clients
> set their constraints, otherwise the balancing code might change the

No, this is not what boot-on means at all.  It is there for cases where
we can't read the enable status from the hardware.  Trying to infer
*anything* about the runtime behaviour from it being present or absent
is very badly broken.

Saravana (CCed) was working on some patches which tried to deal with
some stuff around this for enables using the sync_state() callback.
Unfortunately there's quite a few problems with the current approach
(the biggest one from my point of view being that it's implemented so
that it requires every single consumer of every device on the PMIC to
come up but there's others at more of an implementation level).

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