Currently we are developing small module with iMX6 UltraLite and we have found some issues on USDHC1.
We also have EVK board and it looks like similar issue.
When we try reading in uboot:
mmc read 85000000 0 1
than it is ussualy OK
When we try more blocks
mmc read 85000000 0 100
it ends with ERROR
When we try this even more borad gets stucked in uknown state
Voltage levels on MMC interface drops down to around 1.6 to 1.9V for supply voltage 3.3V
Normally this would not be a big problem because we use NAND flash for normal boot. Issue is that it is not working either in Linux (interface is planned for SDIO WiFi)
We get mmc0: Timeout waiting for hardware interrupt. and error -110
We use customized uboot and kernel forked from officalgit. Our config is attached. Pinconf in uboot and in DTS is same as on EVK board.
USDHC2 is not available on our board but it looks, that is working correctly on EVK.
Original Attachment has been moved to: kernel.cfg.zip