linux-kernel - Re: [PATCH] regulator: core bugfix: Use normal enable for always

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Message-ID: <20140219014615.GK2669@sirena.org.uk>
Date:	Wed, 19 Feb 2014 10:46:15 +0900
From:	Mark Brown <broonie@...nel.org>
To:	Markus Pargmann <mpa@...gutronix.de>
Cc:	Liam Girdwood <lgirdwood@...il.com>, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, kernel@...gutronix.de,
	stable@...r.kernel.org
Subject: Re: [PATCH] regulator: core bugfix: Use normal enable for always_on
 regulators

On Tue, Feb 18, 2014 at 10:40:07PM +0100, Markus Pargmann wrote:
> On Tue, Feb 18, 2014 at 09:14:20AM +0900, Mark Brown wrote:

> > I don't understand this.  Why is this called _no_delay() and why don't
> > we want to delay when applying constraints?  We don't want to ever be in
> > a position where we think a supply is enabled but it has in fact not
> > finished ramping, and of course enable() may in fact be blocking anyway.

> I tried not to modify the current behaviour of the core driver for
> non-gpio regulators. Before this patch only ops->enable() was called
> which also didn't have a delay. So I seperated the non-delay enable
> function to have the same behaviour for normal regulators.

No, that's not good.  The fact that it wasn't applying delays is going
to be a bug - it should've been doing that.

> Also the constraints are applied when registering a new regulator. For
> "boot-on" we should not delay because this regulator is already on by
> definition. But I am not sure what to do with always-on regulators?

I'd just always apply a delay, it's simpler and more robust.

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