I met a problem.
Please see the detail as below.
SD card is not unmounted, and cannot mount any device after that.
In this case, access to the SD card by "ls" command is rejected with the following log.
FAT-fs (mmcblk1p1): Directory bread(block xxx) failed
1. Boot android_jb4.2.2_1.1.0-ga fron eMMC.
2. Settings -> Developer options -> Check "Stay awake".
3. Repeat insert and remove SD card. When remove SD card, don't execute "umount" command, just plug-out.
Maybe very rare.
We repeated insert and remove over 30 min to reproduce this issue.
For your information, the file system in SD card was not broken when this issue was occurred.
Then, we found the system can mount a device after ocurred this issue by the following command.
busybox umount -l /mnt/extsd
However, this solution is not usable for mass production because end user don't use serial console.
So we want to find the root cause and want to know a solution to prevent this issue.
Would you reproduce the same issue and analyze how to prevent it?