This might be a loooong shot in the dark, but...
Many MMC/SD cards need to be fully reset, when left in an "undefined" state. This normally means power supply voltage (at SD card) must drop below 1.3V for a sizable (>100ms) time.
Do you have means to physically remove power to eMMC? Many eMMC chips don't have a usable Reset pin.
HiH Mauro
On 1/25/20 4:42 PM, Amarnath MB wrote:
Hi all,
I working on a T1042RDB based custom board which has a 8GB eMMC (4bit mode) on board. I was able to successfully boot 2019.07 uboot on my board from NOR flash.
After booting, mmcinfo command detects the on board eMMC and displays it's properties. But when I issue mmcinfo command after soft reset through reset command, it gives me mmc_init timeout error.
After adding DEBUG and CONFIG_MMC_TRACE macros to my board header file, i came to know that the eMMC fails to respond to CMD 2.
What can be the issue here? Can anyone guide me?
Regards, Amarnath MB