I’ve got a couple of DragonBoard 410c’s and only recently tried to use an SD card with them. They are both running Linaro-alip 4.2.4 (still as they shipped from Arrow). One of them recognizes the card and automatically mounts it and displays a window asking me if I’d like to view the files. The other DragonBoard does not do this. I can see activity on the LEDs when I insert the card so it seems to recognize that a card has been inserted, but no entries appear in /dev for mmcblk1 as they should. Looking in dmesg I can see the following message is being generated when the card is inserted:
mmc1: Reset 0x1 never completed
If I leave the card inserted and reboot the board then it is seen by Linaro upon reboot. It seems to be a hardware issue of some kind as I’ve tried upgrading to the latest Linaro release (didn’t solve the problem), tried going to Windows 10 IoT (install was successful per the install utility, but it basically just soft-bricked the board as it would not boot at all after that), finally I did a full rescue/recovery via the recovery SD/fastboot method and put it back to the release of Linaro that came on it. That got the board back up and running, but the SD card issue still exists and the ‘mmc1: Reset 0x1 never completed’ error persists. If I want to use an SD card with that particular board I simply have to reboot it. I’ve tried swapping power supplies between board as well and that didn’t amount to much.
At this point I think I just need to exchange the board for a new one.
I’ve seen one other person post the same issue back in late 2015, but he didn’t get an answer to is question then. I’m hoping someone knows something more about this issue and if it is something that can be fixed myself or Not.