linux-kernel - Re: [PATCH v3 0/2] regulator: core: Fix ops->enable/disable usage

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Date:	Mon, 24 Feb 2014 21:50:58 +0100
From:	Markus Pargmann <mpa@...gutronix.de>
To:	Fabio Estevam <festevam@...il.com>
Cc:	Mark Brown <broonie@...nel.org>,
	Sascha Hauer <kernel@...gutronix.de>,
	Liam Girdwood <lgirdwood@...il.com>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 0/2] regulator: core: Fix ops->enable/disable usage

Hi Fabio,

On Mon, Feb 24, 2014 at 02:23:50PM -0300, Fabio Estevam wrote:
> On Sun, Feb 23, 2014 at 2:12 AM, Mark Brown <broonie@...nel.org> wrote:
> > On Thu, Feb 20, 2014 at 05:36:02PM +0100, Markus Pargmann wrote:
> >> Hi,
> >>
> >> These two patches replace all ops->enable/disable by
> >> _regulator_do_disable/enable function calls. These wrappers also handle gpio
> >> regulators.
> >
> > Applied both, thanks.
> 
> With these two patches applied I get the following error on
> mx6qsabresd running today's linux-next:
> 
> vdd1p1: failed to enable
> anatop_regulator regulator-1p1.2: failed to register vdd1p1
> anatop_regulator: probe of regulator-1p1.2 failed with error -22
> vdd3p0: failed to enable
> anatop_regulator regulator-3p0.3: failed to register vdd3p0
> anatop_regulator: probe of regulator-3p0.3 failed with error -22
> vdd2p5: failed to enable
> anatop_regulator regulator-2p5.4: failed to register vdd2p5
> anatop_regulator: probe of regulator-2p5.4 failed with error -22
> vddarm: 725 <--> 1450 mV at 1100 mV
> vddpu: 725 <--> 1450 mV at 1100 mV
> vddsoc: 725 <--> 1450 mV at 1175 mV
> ....
> 
> pfuze100-regulator 1-0008: Full layer: 1, Metal layer: 0
> pfuze100-regulator 1-0008: FAB: 0, FIN: 0
> SW1AB: failed to enable
> pfuze100-regulator 1-0008: register regulatorSW1AB failed
> pfuze100-regulator: probe of 1-0008 failed with error -22
> 
> 
> Reverting these two patches the regulators probe successfully.
> 
> Any ideas?

Thanks, I just searched for the reason and found it. My patches do not
handle dummy regulators correctly:

_regulator_do_enable() line 1764:
        if (rdev->ena_pin) {
                ret = regulator_ena_gpio_ctrl(rdev, true);
                if (ret < 0)
                        return ret;
                rdev->ena_gpio_state = 1;
        } else if (rdev->desc->ops->enable) {
                ret = rdev->desc->ops->enable(rdev);
                if (ret < 0)
                        return ret;
        } else {
                return -EINVAL;
        }

The only situation where this returns -EINVAL is a dummy regulator that
is not always_on. As it doesn't make sense to have a dummy regulator
that is not always_on, I will add a check for exactly this situation to
the regulator_register function and drop the "return -EINVAL" above.

Regards,

Markus

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