BB-xM sdhc error

After some restart the ubuntu I got alot of error while loading the
ubuntu like this

mmcblk0: error -110 transferring data
end_request: I/O error, dev mmcblk0, sector 2397795

some time I got this errors infinitely as sevtor number increasing so
the system could not start

I have reinstall the sdcard but after afew reset again I got these
What is the problem and how can I prevent the damage of the EXT-4 file
system ?

I get similar errors with Angstrom when I use cheap Kingmax and Silicon Power 4Gbyte SD cards. A Toshiba card works without problems.

You could try a different SD card to see if that helps.



It is a known issue. The voltage supplied to the SD card is 3.0V max. You can work around the problem by using a SD card that has higher tolerance. I am using SanDisk Class 4 cards that provide both speed and reliability. I also have good experience with PNY “no speed class” SD card. But, writing data to it is very slow.

Regarding MicroSD card performance there is an interesting blog post
from Steve Sakoman [1].




I notice the tests only go up to 16GB.
I have a 32GB SD card that just won't work. I can create a system on it but part way through an update the errors start and following that it's unbootable, giving a stream of errors that even fsck can't fix.
It will say it's fixed but rerunning fsck will complain of the same errors.

I recall there being a thread on this several months back, but I don't
seeing any resolution. Can you provide any more details?

Do you mean that the Beagle is not supply a high enough voltage and it
wants higher,
or vice versa.

FWIW, I've had good luck with the SanDisk cards as well.


It is the board design for the MMC interface that delivers 3.0V; however, the SD standard calls for 3.3V. I believe the easy solution is to use a high tolerance SD card. Just pay a few dollars more to avoid many hours of frustration and unforeseeable trouble.

IIRC it's 3.15V, not 3.0V. Still not 3.3, though

I checked the SD version 2.0 doc that saved in my PC, it specifies "High Voltage SD Memory Cards that can operate within the voltage range of 2.7-3.6 V". Although the SD voltage of 3.15V comply with the spec, some SD cards indeed failed to work with Beagleboard. Half year ago, I bought 50 "no speed class" SD cards for my 48 Beagleboards, more than half of than failed to make the Beagleboard to boot. But, these failed SD cards works fine with cameras and my USB SD card writer/reader. So, I used the SanDisk Class-4 SD cards instead since I had good experience with them.

P.S. I remember I measured 3.0V with a high-end digital meter. May be my memory did not serve me right.

Anyone know if there are plans to update the beagleboard design to fix this?


There are no plans to change this. The voltage supplied is 3.15V assuming the SW is set correctly. That is well within the SD card specification. A voltage 3.15 is the maximum voltage the TPS65950 can provide.


Yeah, we were looking at the TPS65950 and see that it can output
3.15V. So we need to make sure the all the SW sets it up correctly.
Or am I missing something?