Re: [PATCH 1/1] regulator: max77802: set opmode to normal if off is read from hw
From: Tomasz Figa
Date: Wed Aug 27 2014 - 14:52:58 EST
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.
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