Re: [PATCH v3] mmc: Make ID freq configurable

From: Hein_Tibosch
Date: Fri Aug 27 2010 - 21:17:54 EST


On 28-8-2010 04:44, Chris Ball wrote:
> Hi,
>
> This looks like the best of the min_freq patches I've seen, and is
> implementing a suggestion of Pierre's. Should we take it?
>
> - Chris.
>
> On Tue, Jan 05, 2010 at 05:58:34AM +0800, Hein_Tibosch wrote:
>> Below a patch which tries mmc-initialization using several frequencies
>> from an array 400, 300, 200 and 100.
>>
>>
>> Signed-off-by: Hein Tibosch <hein_tibosch@xxxxxxxx>
>> <cut>
Hi Chris,

Thanks. I can confirm that the above patch has been working properly for
7 months now, using various SD-cards.

Here it tries 3 frequencies, which takes 290 ms:

000 mmc_rescan: trying 400000 Hz
Waiting 1sec before mounting root device...
061 mci: F now 400000 (actual 397727)
usb 1-2: configuration #1 chosen from 1 choice
126 mmc_rescan: trying 300000 Hz
input: eGalax Inc. USB TouchController as /class/input/input1
193 mci: F now 300000 (actual 299145)
227 mmc_rescan: trying 200000 Hz
255 mci: F now 200000 (actual 200000)
290 mmc0: new SD card at address e624

In a meanwhile it is doing other things, so not much time is wasted.
But most importantly: it never failed to initialize a card.

Hein Tibosch
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