[PATCH v2 1/2] ARM: vexpress: Enable regulator framework when MMCI is in use

[Ulf Hansson]

On 18 March 2013 22:40, Arnd Bergmann <arnd at arndb.de> wrote:
> On Monday 18 March 2013, Russell King - ARM Linux wrote:
>> On Mon, Mar 18, 2013 at 06:16:57PM +0000, Pawel Moll wrote:
>> >
>> > Reverting it will not change anything as the driver had the same
>> > dependency before, just using :
>>
>> Umm.  If CONFIG_REGULATOR is not set with the patch reverted, the
>> regulator support is not used at all, and the ocrmask comes from
>> the platform data.
>
> I think the point is that case of DT booting, the platform data has
> a zero ocrmask, because Versatile Express has no auxdata to set
> a platform_data pointer for the mmci device, and the default allocated
> mmci device driver does not initialize the ocrmask unless the
> regulator API is used.
>
> This took me a while to figure out, the point being that this is not
> actually a regression, it never worked as far as I can tell.
>
> I don't think that selecting the regulator API is a good idea, for
> the reasons that you mentioned, and I still wouldn't take the
> patch. In theory we could do a workaround by adding a DT property
> to the mmci node that describes the fixed voltage supplied to the
> card if there are no regulators, but then again we already describe
> the voltage using the regulator binding and I would not want to
> duplicate that information.
>
> What I think we should have though is a better diagnostic here:
> If neither the platform data nor the DT contain a valid description
> of the voltage supplied to the card, the probe should fail saying
> that the information is missing, not that the card is incompatible.
>
>         Arnd

I agree Arnd.

If mmci during probe, don't get a regulator and don't have an OCR mask
from dt/platform data, probe should fail.

Kind regards
Ulf Hansson