linux-kernel - Re: [PATCH 3/6] regulator: lp872x: Remove warning about invalid DVS GPIO

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Message-ID: <20151223115838.GT16023@sirena.org.uk>
Date:	Wed, 23 Dec 2015 11:58:38 +0000
From:	Mark Brown <broonie@...nel.org>
To:	Paul Kocialkowski <contact@...lk.fr>
Cc:	linux-kernel@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Russell King <linux@....linux.org.uk>,
	Benoît Cousson <bcousson@...libre.com>,
	Tony Lindgren <tony@...mide.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	Milo Kim <milo.kim@...com>, devicetree@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-omap@...r.kernel.org
Subject: Re: [PATCH 3/6] regulator: lp872x: Remove warning about invalid DVS
 GPIO

On Wed, Dec 23, 2015 at 12:50:20PM +0100, Paul Kocialkowski wrote:
> Le mercredi 23 décembre 2015 à 11:41 +0000, Mark Brown a écrit :

> > I would expect the driver at least needs to know how the pins or
> > strapped, or otherwise have configuration for ignoring the input on the
> > pins.  This just deletes the warnings, it doesn't have any handling for
> > this case that I can see.

> When the DVS GPIO is invalid, lp872x_init_dvs jumps to the
> set_default_dvs_mode label, which instructs the chip not to use the DVS
> pin at all and do it all in software instead (by clearing the
> LP8720_EXT_DVS_M bit in the LP872X_GENERAL_CFG register).

> That is reflected later in the code, when setting the bucks (the DVS pin
> only applies to the bucks) by checking for the LP8720_EXT_DVS_M bit on
> the LP872X_GENERAL_CFG register (in lp872x_select_buck_vout_addr) to
> decide whether to use software or hardware DVS selection.

> As far as I understood, everything goes well when the GPIO is invalid.

So please put this analysis in the changelog so that the changelog
accurately reflects what the change is doing.

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