SD Cards not detected by Linux

Hi Robert,
I found that SD cards used and flashed with BBBw Images ( dd copied ) are not detected when plugged into SD card reader on Linux PC. The errors are mmc0: error -110 whilst initialising SD card
But if it is plugged in with a usb sd card reader, it can be detected. ( listed as /dev/sda, /dev/sda1)

Thank You,

Error 110 is: ETIMEDOUT

 #define	ETIMEDOUT	110	/* Connection timed out */

So while your device “detected” something it was unable to connect… Either worn or dirty pin’s on the connector, or a bad usb cable, or just a failing adapter.


Hi Robert,

Thank you for your prompt reply.
I tried several SD cards. It seems they are not worn or dirty pins. If those cards plugged into BBBw SD card reader on BBBw dev boards, they can be detected as /dev/mmcblk0 and /dev/mmcblkp1. lsblk command also lists those devices.
But If I plugged them into Ubuntu PC, dmesg shows many errors. ls, lsblk, lsusb commands show no devices.

If I plug them using USB sd card reader (plugged into usb port) into Ubuntu PC, it is listed as /dev/sdb. If fdisk /dev/sdb, it returns fdisk: cannot access '/dev/sdb: no media found.

Both usb sd card reader and sd reader are ok if a normal sd card is plugged in.

Best Regards,

Hi David,
what’s the density of your several Secure Digital (SD) cards you tried ?
It could be that just the physical size is too big to be recognised by your
system and therefore they cannot be initialized at all.
In the past there was a limit of 128kByte for some flash File Systems (FS).
Regards, Rolf

Sadly, with a -110 error, it will never get to that stage of the driver pipeline. Basically it’s detected a media device, but can not communicate with it.


Hi All,
My SD card is 32G. One is burned, and also it burned BBBw board. The sd card holder overheated. And the BBBw runs without sd card plugged in. Otherwise, it terminates kernel.

Other sd cards, may be also overheated. I don’t know for sure.

Best Regards,

That’s not supposed to happen… That it did is indicative of some manner of short circuit, which could be caused by a number of things. My guess would be a damaged/defective/counterfeit SD card, though a defect in the card connector causing incorrect connections to be made would be another possibility.

Fake flash memory products are not uncommon, and can range from being empty packages to having less than advertised capacity to being produced with chips that failed quality control testing, or that were never tested at all. It seems likely to me that cards produced with bad silicon would show symptoms like those that are described.

Hi Rick,

I have SanDisk Ultra Plus (several cards) , ordered through DIGIKEY, (or mouser ) .

Best Regards,

It’s been a few (many) years since we’ve had SanDisk (microSD/SD) products in stock.

I’ve had really good luck with these SLC based microSD cards from Swissbit, they are more expensive, but being SLC based, they are quite reliable…


Rob’s observation regarding DK’s stock of SanDisk products appears correct–I’d add that I’m not finding products with the mentioned branding listed at mouser either. If you could provide a specific part number, salesorder number, or invoice number for products purchased through DK, it’d be possible to look for reports of any similar issues from other customers.

Has the BBBw board in question been used with other SD cards successfully? If not, it would seem possible that there’s a defect on the board itself that’s causing the issue.

Hi Both,
I have ordered a few more BBBw, and I may have to order some SD cards. I will keep an eye on this and handle with care.

Best Regards,