Re: [PATCH 1/1] regulator: max77802: set opmode to normal if off is read from hw

From: Tomasz Figa
Date: Wed Aug 27 2014 - 14:39:54 EST


On 27.08.2014 20:37, Mark Brown wrote:
> On Wed, Aug 27, 2014 at 08:32:38PM +0200, Tomasz Figa wrote:
>> On 26.08.2014 13:37, Javier Martinez Canillas wrote:
>
>>> + /*
>>> + * If the regulator is disabled and the system warm rebooted,
>>> + * the hardware reports OFF as the regulator operating mode.
>>> + * Default to operating mode NORMAL in that case.
>>> + */
>>> + if (val == MAX77802_OPMODE_OFF)
>>> + max77802->opmode[id] = MAX77802_OPMODE_NORMAL;
>>> + else
>>> + max77802->opmode[id] = val;
>
>> I might be missing something, but I believe I see a flaw here. If after
>> a cold boot opmode is something else than OFF or NORMAL, the kernel
>> starts, turns the regulator off and does warm reboot, the setting is
>> lost and the regulator is switched to NORMAL mode.
>
> 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).
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