unable to read from Sandisk 8Gb SD

Previdi Roberto previdi.roberto at gmail.com
Mon Sep 15 19:50:14 CEST 2008

On Mon, Sep 15, 2008 at 9:13 AM, Andy Green <andy at openmoko.com> wrote:

> Can you confirm if you need the idle clock set to 1?  What I think I
> understood about this issue is that it is timeout-related only, it means
> I didn't actually understand what is going on if it needs idle clocks too.

i am now sure: i don't need it. I made many other experiments (about
log2(50)) and i found out that the maximum value for the sd_max_clock which
can still read the card is

int(50MHz / 19) =2631578 Hz

(why this value? maybe something crucial happens at low level when you raise
from this value?)
Anyway, i don't absolutely need the idleclock, it was just one of the thing
tried to make it work.
Probably the problem is just that i bought a very slow card.. I hope that
performances will be sufficient to boot something from it, or maybe i could
keep it just to save my mp3s..

i attach my u-boot environment, just in case anyone pass through the same
pain he can try to take inspiration from it. the menus which successfully
boot with the card are the 4 and the 10.

if any other test could be useful to debug just tell me what to do.. at the
moment i don't mind loosing the card content, i just put an experimental
environment inside, and it seems not to boot very well..

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