Re: [PATCH v4 4/4] regulator: Prevent falling too fast

From	Mark Brown <broonie@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v4 4/4] regulator: Prevent falling too fast
Date	2016-12-13 18:20 +0100
Message-ID	<sNYUa-3UP-15@gated-at.bofh.it> (permalink)
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On Mon, Dec 12, 2016 at 01:15:02PM -0800, Matthias Kaehlcke wrote:
> El Fri, Oct 28, 2016 at 07:15:21PM +0100 Mark Brown ha dit:
> > On Mon, Sep 26, 2016 at 10:41:59AM -0700, Doug Anderson wrote:

> > What you're describing to me is a discrete DCDC that has an input
> > voltage that sets the output voltage which happens to be set with a PWM.

> I experimented a bit with this. Besides the question of how to model
> the passives I wonder how the two regulators would interact. The
> correct thing seems to be to specify the input regulator as a supply
> of the DCDC. dcdc->set_voltage breaks down a voltage transition into

No, not unless the prior descriptions of the hardware have been wildly
inaccurate - my understanding had been that the DCDC was a normal DCDC
with an analogue input intended to be biased to set the output voltage
(presumably in terms of a full rail supply) and that the PWM had been
connected to this analogue input.  If the PWM is supplying the DCDC then 
the hardware design just seems bizzare, I can't see how this would even
work.

Thread

Re: [PATCH v4 4/4] regulator: Prevent falling too fast Matthias Kaehlcke <mka@chromium.org> - 2016-12-12 22:20 +0100
  Re: [PATCH v4 4/4] regulator: Prevent falling too fast Mark Brown <broonie@kernel.org> - 2016-12-13 18:20 +0100
    Re: [PATCH v4 4/4] regulator: Prevent falling too fast Doug Anderson <dianders@chromium.org> - 2016-12-13 21:10 +0100
      Re: [PATCH v4 4/4] regulator: Prevent falling too fast Matthias Kaehlcke <mka@chromium.org> - 2016-12-14 00:20 +0100
      Re: [PATCH v4 4/4] regulator: Prevent falling too fast Mark Brown <broonie@kernel.org> - 2016-12-14 14:30 +0100

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