filed http://dev.laptop.org/ticket/12216
Jerry 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. > > Thanks, > wad > > 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 > > > > _______________________________________________ > > Devel mailing list > > Devel@lists.laptop.org > > http://lists.laptop.org/listinfo/devel > > _______________________________________________ > Devel mailing list > Devel@lists.laptop.org > http://lists.laptop.org/listinfo/devel _______________________________________________ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel