Announcing Q4D06 for XO-1.75

Chris Ball cjb at
Tue Mar 27 09:17:12 EDT 2012


Thanks for debugging this!

On Tue, Mar 27 2012, Sascha Silbe wrote:
> Excerpts from Chris Ball's message of 2012-03-26 20:36:21 +0200:
>> > I'm specifically asking because recent kernels don't like my SD card
>> > (only one in about twenty or fifty boots succeeds; two different
>> > failure modes), so I'd need to make sure I diagnose and fix that
>> > before upgrading OFW the next time.
>> That sounds bad, what are the failure modes?
> The first, more common one is that the card is detected, but cannot be
> read from:
> [  664.720232] mmc0: new ultra high speed SDHC card at address e624

I haven't used a UHS-I card before, so you're in uncharted territory.  :)

> git bisect blames the following OLPC commit:
> 39fc327e8d541d146528f03150fec36189e4dac5 is the first bad commit
> commit 39fc327e8d541d146528f03150fec36189e4dac5
> Author: Andres Salomon <dilinger at>
> Date:   Thu Dec 22 16:28:55 2011 -0800
>     sdhci-pxa: add retuning of timing in the case of CRC errors
>     This is only for the !wlan devices.
>     Signed-off-by: Andres Salomon <dilinger at>

That's very interesting.  Does reverting this commit result in a kernel
that boots every time, then?

- Chris.
Chris Ball   <cjb at>   <>
One Laptop Per Child

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