Re: [PATCH v9 1/2] regulator: Add driver for max77802 PMIC PMIC regulators

Doug Anderson
2014-08-22T22:15:09Z

Hi,

On Fri, Aug 22, 2014 at 3:02 PM, Javier Martinez Canillas
<javier.martinez@collabora.co.uk> wrote:
> Hello Mark,
>
> On 08/22/2014 08:30 PM, Mark Brown wrote:
>>
>>> The problem is that one of these regulators is used as the vqmmc-supply
>>> (VCCQ/VDD_IO) so the mmc host controller driver disables it on
>>> MMC_POWER_OFF. Now AFAIK (Yuvaraj can correct me what I got wrong) this
>>> shouldn't be an issue since on card detection, the vqmmc supply should be
>>> enabled again but on Exynos the built-in card detect line is on the same
>>> power rail as vqmmc. That means that disabling the regulator prevents card
>>> insertions to be detected.
>>
>> If the MMC host controller needs a supply enabling in order to do card
>> detection and it's supposed to be doing card detection I'd expect it to
>> be enabling that supply. Why is it not doing that?
>>
>
> Good question. I'm not that familiar with the dw_mmc host controller nor
> its driver implementation so I'll let Yuvaraj or Doug to answer that.

I haven't seen the issue that Yuvaraj is reporting (but I also haven't
picked up all of the relevant patches and tried to reproduce), so I'm
going to have to leave it to Yuvaraj to answer.

As far as I know the dw_mmc driver ought to be enabling vqmmc when it
needs it. Perhaps there's a bug in your patch series that adds vqmmc
support to dw_mmc?

-Doug