Sandisk extreme 32GB and 16GB dont initialize in XO-1.75
jvonau at shaw.ca
Thu Oct 18 15:16:24 EDT 2012
On Thu, 2012-10-18 at 14:48 -0400, John Watlington wrote:
> Based on that error message, my guess is that those Sandisk cards are the
> first to support +1.8V operation. The kernel is detecting this, but getting
> confused as it doesn't know how to turn on +1.8V power to the SD (it isn't
> supported by that motherboard).
> On XO-1.5, we supported operating SD cards at +1.8V, but since we never
> encountered such a card the feature was dropped in XO-1.75/XO-4. All cards
> have to support operation at the +3.3V these systems provide.
> The kernel should recognize this limitation, and not try to negotiate for
> lower voltages. This sounds like a bug in build 21, please file a ticket.
> On Oct 7, 2012, at 7:33 AM, George Hunt wrote:
> > Hi all,
> > I've been working on a XO-1.75 as XS project. The smallest form factor XS would use an SD card for School Server storage. So I purchased fast, large SD cards from Amazon. These cards work in my mac, and they initialize, and appear to work on the XO-1.5 running build 860.
> > The XO-1.75 software is build 21 (12.1.0), firmware is Q4D17.
> > The error message in the /var/log/messages is:
> > Oct 7 11:18:44 schoolserver kernel: [157819.866661] sdhci: Switching to 1.8V signalling voltage failed, retrying with S18R set to 0
> > Oct 7 11:18:44 schoolserver kernel: [157819.876896] mmc0: error -110 whilst initialising SD card
> > In my reading about SD cards, I discover that some SD cards are not genuine. I have looked at /sys/... and the manufacturing number was "003" which is appropriate for sandisk.
> > This error message is mentioned in
> > Ticket #11736
> > I'd be happy to give more info, or do testing.
> > George
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