linux-kernel - Re: [PATCH] regulator: core: if voltage scaling fails, restore original

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Date:	Thu, 13 Dec 2012 05:06:28 +0000 (UTC)
From:	Paul Walmsley <paul@...an.com>
To:	Paolo Pisati <paolo.pisati@...onical.com>
cc:	linux-omap <linux-omap@...r.kernel.org>,
	Liam Girdwood <lrg@...com>,
	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] regulator: core: if voltage scaling fails, restore
 original

On Wed, 12 Dec 2012, Paolo Pisati wrote:

> but inside regulator_set_voltage(), we save the new regulator voltage before
> actually ramping up:
> 
> core.c::regulator_set_voltage():
> 	...
>     regulator->min_uV = min_uV;
>     regulator->max_uV = max_uV;
> 
>     ret = regulator_check_consumers(rdev, &min_uV, &max_uV);
>     if (ret < 0)
>         goto out2;
> 
>     ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);  <-- ERROR!!!
>     if (ret < 0)
>         goto out2;
> 	...

I'm not too familiar with this code.  But isn't this where the bug is, 
rather than in that optimization commit you mentioned?  Seems to me, 
naïvely, that in the above code, regulator->min_uV and regulator->max_uV 
should be set only after _regulator_do_set_voltage() succeeds?


- Paul