[U-Boot] Nokia N900 - eMMC not working after commit 02f3029f1810b99869254d0cf0a71946a008a728

[Macpaul Lin]

Hi Lei Wen,

2011/11/15 Lei Wen <adrian.wenl at gmail.com>:
> Hi Macpaul,
>
>> Figure 6.1
>> http://i.imgur.com/bmoAX.jpg
>> Figure 6.2
>> http://i.imgur.com/7fxdx.jpg
>>
>> As you can see, after the power ramp up to 74 clocks (1msec), the CMD0
>> can be send to the card.
>>
>> So it seems your controller will do power ramp up (dynamic clock
>> gating?) "only after" the CMD0 has been send?
>> Is this correct? However, it is weird and seem not followed the specification.
>
> Yes, our controller use dynamic control gating for clock. The clock is
> not sample out
> while no command send out.
>
> I realize now we at least cannot directly return err if the cmd8 is not succeed.
> Please submit a patch to fix it.
>
> Thanks,
> Lei
>

It seems your hardware doesn't follow the rule that specification
described and made
compatibility problem to other platform, includes the existing platforms.
I think you'd better report it to your hardware designer which is a
hardware bug need to be fixed.
And, I think you can send a quick fix patch like the #ifdef
as you've mention to workaround for your hardware "only" if you cannot
find a common solution right now.

-- 
Best regards,
Macpaul Lin