Re: [PATCH] mmc: omap_hsmmc: Add small delay after enabling power

Stefan Roese
2014-09-12T07:26:19Z

On 11.09.2014 16:15, Ulf Hansson wrote:
> On 11 September 2014 16:11, Stefan Roese <sr@denx.de> wrote:
>> From: Thorsten Einsbein <thorsten.eisbein@head-acoustics.de>
>>
>> On the TAO3530 (OMAP3530 based) we noticed that some SD cards are not
>> detected reliably upon bootup (timeout). Especially the SanDisk Ultra
>> 8GiB seems to be problematic here. The SanDisk Extreme also has this
>> problem on this platform, but not that often. A Samsung 8 GiB type 6
>> doesn't show this problem at all.
>>
>> This patch now adds a short delay after enabling the power on the slot.
>> With this delay all cards are detected reliably.
>
> Is this delay related to regulator ramp up/down time? Then I think it
> maybe should be a part of the regulator code/DT.

Thanks for this feedback. Yes, adding "regulator-enable-ramp-delay" to
the regulator(s) solves this issue too. I wasn't aware of that one.

The patch can be dropped.

Thanks,
Stefan