eMMC fails while booting mx28

[vinugopalakrish]

Hi NXP support,

We have designed a new board based on mx28. The board bring up is blocked due to some issues with MMC. The issue is present in both u-boot and kernel. The eMMC initialization is failing randomly in uboot. Once the u-boot successfully initialises MMC , we are able to erase, write and read back seamlessly. 

However in kernel the issue is consistent and is blocking the booting process. The kernel and rootfs are loaded successfully from MMC but towards the end we see MMC timeout error which eventually blocks the booting from reaching the login prompt.

Please see the logs attached.

Details:

IMX28

U-Boot 2014.01 (Mar 25 2020 - 15:53:52)

kernel - linux-imx 2.6.35.3

Yocto build system with freescale bsp version imx-3.10.53-1.1.0_ga

emmc part - IS21ES04G-JCLI

Please note that the eMMC is jedec 5.0 and the imx driver supports upto 4.5. 

Any help would be greatly appreciated.

regards,

Vinu

[vinugopalakrish]

Ok, so we have to migrate to the new BSP. Can you please share the links to the latest stable mx28 BSP ?

Thanks,

Vinu

[igorpadykov]

Hi Vinu

latest nxp offical stable i.MX28 BSP

is i.MX28 Linux 2.6.35 Source Code Files and documentationSo one can test it with i.MX28 EVK and try to reproduce issue with it.

Best regards
igor

[vinugopalakrish]

Hi Igor,

Drive strength didn't make any difference. We found that the issue is with kernel mmc driver because a latest bsp and kernel is running smoothly.

Further details:

When an image with minimal rootfs containing basic app packages is flashed and booted from eMMC, the kernel and rootfs are loaded successfully, however we see an MMC timeout error which eventually blocks the booting from reaching the login prompt.
Please see the attached the error logs.

Following are the Details:
IMX28 based custom board with based on mx28evk design with eMMC
U-Boot 2014.01 (Mar 25 2020 - 15:53:52)
Kernel - linux-imx 2.6.35.3
Yocto build system with Freescale BSP version imx-3.10.53-1.1.0_ga
eMMC part - IS21ES04G-JCLI (Jedec 5.0)

Question 1: What are the changes to be done in the above kernel/mmc driver to port from SD card to eMMC? Please list the same.
Question 2: As the custom board eMMC doesnt have WP and card detect pins, do we need to make any specific changes in the source?

Note: The freescale mx28 BSP that we use has an old kernel (non DT based ).

regards,

Vinu

[igorpadykov]

Hi Vinu

these bsps are outdated and not more supported, suggest to

proceed with help of  Commercial Support and Engineering Services | NXP 

Best regards
igor

[vinugopalakrish]

Is it possible to modify the obds tool source and make the test more intensive so that we can make sure that eMMC is not failing under heavy load?
Please note that currently we are not using GDB and JTAG is unavailable.

I'll also try changing the drive strength in kernel and see if it makes any difference.

regards,

Vinu 

[igorpadykov]

Hi Vinu

one can look at below i.MX6Q emmc stability issues and try different emmc:

eMMC 8GB to 4GB - crash on linux (yocto) boot 

For i.MX28 one can check sect.9.2.2.1 Pin Drive Strength Selection Reference Manual.

Baremetal emmc test can be performed with On-Board Diagnostic Suit for the i.MX28

Best regards
igor
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[vinugopalakrish]

Hi Igor,

We run the Baremetal emmc test for SD card and it was success. Please see the log -

********************************************************
Diagnostics Suite (1.0) on i.MX28 evk
Build: Mar 26 2020, 11:39:06
Freescale Semiconductor, Inc.
********************************************************

---- Running < SD CARD > test
Please enter y or Y to confirm
input char is: Y
RESP_TIMEOUT_IRQ
RESP_TIMEOUT_IRQ
RESP_TIMEOUT_IRQ
Bus Width: 8
[RESULT] SD Test Pass.

regards,

Vinu

[igorpadykov]

Hi Vinu

you can try to find what command causes emmc error, debugging

image with  AN4553 Using Open Source Debugging Tools for Linux on i.MX Processors

then test the same emmc command with baremetal test.

Try to cool, if cooling causes more failures, then it is likely the drive strength is too high.

Best regards
igor

[vinugopalakrish]

Also please share any link/app note/source code that can be used as reference material.