microSD slot fried?

Andy Green andy at openmoko.com
Fri Sep 12 10:58:22 CEST 2008

Hash: SHA1

Somebody in the thread at some point said:

| mmcblk0: mmc0:b360 USD   7070656KiB
|  mmcblk0:<6>glamo-mci glamo-mci.0: Error after cmd: 0x8310
|> glamo_mci.sd_max_clk=10000000
| This did help, I followed instructions at
| http://docs.openmoko.org/trac/ticket/1743
| How is it possible that a previously working card suddenly becomes
| non-working without the max clk, I wonder?

The issue here is that timeout on Glamo MCI is in units of MMC clocks,
but part of the latency for data access to the NAND in the card is in
absolute time.  So for example, it takes 100ms to get the data off the
memory in the card.

The absolute time that passes in the Glamo timeout depends entirely on
the clock speed, it's double the duration at 12.5MHz than it is at 25MHz
for example.

So reduction of clock here is just extending the absolute timeout period
to match what your (slow) card needs.

- -Andy
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org


More information about the support mailing list