mmc init fails after soft reset on T1042

[Mauro Condarelli]

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
>