AnsweredAssumed Answered

Slow down sd card on imx6q

Question asked by j b on Jul 8, 2014
Latest reply on Apr 5, 2015 by Sriram Periyasamy

I'm booting my imx6q off an sd card on custom hardware.  Uboot works fine but during the boot of the linux kernel I get an error reading the sd card. 

 

mmcblk1: error -84 transferring data, sector 0, nr 8, cmd response 0x900, card status 0xb00

 

I don't always get this error.  Booting two different SD cards (one class 2 and one class 4) the class 2 card throws the error while the class 4 card successfully boots. With the class 4 card I can get all the way to the log-in prompt.  Given the flaky nature of booting off the sdcard slot, I'm guessing my problem may be that the distance between my sdcard slot and the cpu is too long.  I'd like to slow down reading from the sd card to see if this increases my boot fidelity.  How can you slow down reading from and sdcard on the imx6q?

Outcomes