linux-kernel - Re: [PATCH v5 3/4] regulator: max77686: Add suspend disable for some LDOs

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Message-id: <1414574413.18868.6.camel@AMDC1943>
Date:	Wed, 29 Oct 2014 10:20:13 +0100
From:	Krzysztof Kozlowski <k.kozlowski@...sung.com>
To:	Mark Brown <broonie@...nel.org>
Cc:	Liam Girdwood <lgirdwood@...il.com>, linux-kernel@...r.kernel.org,
	Ben Dooks <ben-linux@...ff.org>,
	Kukjin Kim <kgene.kim@...sung.com>,
	Russell King <linux@....linux.org.uk>,
	linux-arm-kernel@...ts.infradead.org,
	linux-samsung-soc@...r.kernel.org, devicetree@...r.kernel.org,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Marek Szyprowski <m.szyprowski@...sung.com>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
	Javier Martinez Canillas <javier.martinez@...labora.co.uk>,
	Chanwoo Choi <cw00.choi@...sung.com>
Subject: Re: [PATCH v5 3/4] regulator: max77686: Add suspend disable for some
 LDOs

On wto, 2014-10-28 at 22:31 +0000, Mark Brown wrote:
> On Mon, Oct 27, 2014 at 01:11:49PM +0100, Krzysztof Kozlowski wrote:
> 
> > @@ -247,6 +250,8 @@ static struct regulator_ops max77686_ldo_ops = {
> >  	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
> >  	.set_voltage_time_sel	= regulator_set_voltage_time_sel,
> >  	.set_suspend_mode	= max77686_ldo_set_suspend_mode,
> > +	.set_suspend_disable	= max77686_set_suspend_disable,
> > +	.set_suspend_enable	= max77686_enable,
> 
> This looks wrong, you're using the regular enable operation as suspend
> enable.  How does that work without disrupting the current runtime
> state?

Currently it shouldn't disrupt state of regulator because during runtime
it may only be only: on (0x3) or off (0x0). Suspend enable in max77686
writes 0x3 to the register which means - always on.

If regulator was disabled before suspend then it has to be enabled
during suspend_enable() call which is exactly what max77686_enable does.
If it was enabled then nothing happens.

Best regards,
Krzysztof

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