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From: Tomasz Figa <tomasz.figa@gmail.com>
To: Mark Brown <broonie@kernel.org>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>,
	Doug Anderson <dianders@chromium.org>,
	Olof Johansson <olof@lixom.net>,
	Yuvaraj Kumar C D <yuvaraj.cd@gmail.com>,
	linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] regulator: max77802: set opmode to normal if off is read from hw
Date: Wed, 27 Aug 2014 20:52:49 +0200	[thread overview]
Message-ID: <53FE2901.50508@gmail.com> (raw)
In-Reply-To: <20140827184705.GO17528@sirena.org.uk>

On 27.08.2014 20:47, Mark Brown wrote:
> On Wed, Aug 27, 2014 at 08:39:39PM +0200, Tomasz Figa wrote:
>> On 27.08.2014 20:37, Mark Brown wrote:
> 
>>> That's essentially the situation the patch is trying to fix - if we boot
>>> and the regulator is off there's no way to figure out what the operating
>>> mode would have been so we have to pick something.  If you've got an
>>> idea for something better to do...
> 
>> Probably the only way to correctly handle this is to specify the right
>> operating mode in DT (after defining a binding for it).
> 
> I'm not convinced that's worth it - chances are that if anything changed
> the mode it was a previously running Linux which will most likely be
> doing the same things when it starts running anyway.
> 

The previously running Linux would have changed the opmode accidentally,
due to hardware design of PMIC chip, which doesn't allow powering off a
regulator in other way than setting opmode to OFF.

If you provide the "active" opmode to that Linux, after a warm reboot it
will be able to power on such regulator to correct opmode, without
defaulting it incorrectly to NORMAL.

  reply	other threads:[~2014-08-27 18:52 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-26 11:37 [PATCH 1/1] regulator: max77802: set opmode to normal if off is read from hw Javier Martinez Canillas
2014-08-26 15:44 ` Doug Anderson
2014-08-27  6:47 ` Yuvaraj Kumar
2014-08-27 17:51 ` Mark Brown
2014-08-27 18:32 ` Tomasz Figa
2014-08-27 18:37   ` Mark Brown
2014-08-27 18:39     ` Tomasz Figa
2014-08-27 18:47       ` Mark Brown
2014-08-27 18:52         ` Tomasz Figa [this message]
2014-08-27 19:15           ` Mark Brown
2014-08-27 19:21             ` Tomasz Figa
2014-08-27 19:44               ` Mark Brown
2014-08-27 19:58                 ` Tomasz Figa
2014-08-27 20:25                   ` Mark Brown
2014-08-27 20:41                     ` Tomasz Figa
2014-08-27 21:03                       ` Tomasz Figa
2014-08-27 22:44                         ` Javier Martinez Canillas
2014-08-28  8:28                           ` Mark Brown
2014-08-28  9:59                             ` Javier Martinez Canillas
2014-08-28 10:01                               ` Mark Brown
2014-08-27 21:03                       ` Mark Brown

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