I have i.MX6qdl board where usdhc3 is designed for SD card slot. I'm using Linux from linux-2.6-imx.git - Freescale i.MX Linux Tree with imx_4.1.15_1.0.0_ga tag.
On the Linux, I have a continuous /dev/urandom test followed by pattern(attached sd_test.sh). Test seems working with single iteration after that it triggers mmc errors. So when I take the card from target and plug-in to host the card seems not mountable, but able to see the partitions.
Here are the pads, I have used:
Here are the Linux frequency details.
# cat /sys/kernel/debug/mmc0/ios
clock: 50000000 Hz
actual clock: 49500000 Hz
# cat /sys/kernel/debug/mmc0/clock
Attached kernel_sd.log for boot log and mmc issues.
Any inputs please let us know.