linux-kernel - Re: [PATCH 2/2] regulator: core: Ensure we are at least in bounds for our constraints

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Date:	Mon, 28 Mar 2016 09:16:15 -0700
From:	Bjorn Andersson <bjorn.andersson@...aro.org>
To:	Mark Brown <broonie@...nel.org>
Cc:	Bjorn Andersson <bjorn@...o.se>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	Ivaylo Dimitrov <ivo.g.dimitrov.75@...il.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	linux-mmc <linux-mmc@...r.kernel.org>,
	linux-samsung-soc <linux-samsung-soc@...r.kernel.org>,
	Javier Martinez Canillas <javier@....samsung.com>,
	Marek Szyprowski <m.szyprowski@...sung.com>
Subject: Re: [PATCH 2/2] regulator: core: Ensure we are at least in bounds for
 our constraints

On Sun, Mar 27, 2016 at 2:08 AM, Mark Brown <broonie@...nel.org> wrote:
> On Sat, Mar 26, 2016 at 04:50:41PM -0700, Bjorn Andersson wrote:
>
>> Reinstating the following snippet in of_get_regulation_constraints()
>> sort this out:
>
>> if (constraints->min_uV && constraints->max_uV)
>>                                        constraints->apply_uV = true;
>
> The existing check in the patch should be an || not an ==, or possibly
> we should just not bother looking for min_uV at all.  I just pushed out
> a version of that, let's see how that goes.
>

Either way is fine with me, as long as we either go ahead and apply a
voltage setting now or allow a consumer to do so later (your posted
patch does both).

>> I did look at an alternative of having regulator_set_voltage() pass
>> and call set_voltage() if the requested voltage matches the
>> constraints, but this does indeed seem to mess things up. So checking
>> in with you before continuing on that hack.
>
> Yes, not everything is writeable.

Right, looking at your posted patch [1] we're changing this logic so
that normal regulators defined with min == max will be allowed to
set_voltage(). Thinking about it that makes sense and cleans the logic
up, so I'm in favor of this.

I know it's published, but fwiw you have my Acked-by on the posted patch.


[1] https://git.kernel.org/cgit/linux/kernel/git/broonie/regulator.git/commit/?h=for-next&id=fa93fd4ecc9c58475abac6db93a797bff893bc16

Regards,
Bjorn