System Reset Issue on i.MX91 and i.MX93

[yaen]

Dear NXP Support Team,

I have observed that the system reset is not working on the i.MX91 and iMX93 in both U-Boot and kernel.

It began after transitioning to U-Boot 2024.04 as part of Yocto scarthgap

I have investigated the ATF component but ATF hash in U-Boot 2023.04 and 2024.04 is identical (lf_v2.10 49143a170) as well as bl31.bin

I am uncertain about the root cause and would appreciate your expertise in identifying potential areas for investigation.

Are you aware of any similar reset issues with these platforms?

Do you have any recommendations for further debugging or isolating this issue?

I would be happy to provide any additional information or perform any tests you might need to assist in resolving this problem. Thank you for your time and support.

Best regards,

Yaakov Entin

C-LAB

[yaen]

Hi,

Here are my steps:

build :

bitbake imx-boot

in other window i run:

watch uuu -lsusb

when i power on the board or reset via HW button, i see "SDPS"

boot:

sudo uuu imx-boot-tagged

reset the board:

reset

Now i expect to see "SDPS" in the above watch window but it is empty.

Si version:

CPU: NXP i.MX91(31) Rev1.0 A55 at 1400 MHz at 46C

Thanks

[Manuel_Salas]

Hello @yaen 

I believe this behavior is expected, you can try to set your board in serial download mode, or you can set the command:

fastboot 0

in U-boot, then you will be able to see the USB ID board with UUU.

Best regards,

Salas.

[yaen]

Hi @Manuel_Salas ,

The SoC is in serial download mode and working normally .

The problem starts when i reset via command and then i see the above observation of essentially a hang of the reset apparently because of wdog3.

[Manuel_Salas]

Hello @yaen 

I hope you are doing well.

We have reported an issue with the i.MX93 (also it appears to affects to i.MX91) that you can poweroff by command the board but after of ~45 minutes the board turn on again.

I am not sure if this is the issue that you are having.

Could you please describe your exact issue?

Best regards,

Salas.

[yaen]

Hi @Manuel_Salas ,

I am talking about something else.

I am using uuu. When i run 'reset' in U-Boot, and 'uuu -lsusb' on host, host does not recognize SDPS connection to the SoC as it should and cannot push bootloader.

hard reset does work and doing the same with U-Boot 2023.04 too.

[Manuel_Salas]

Hello @yaen 

Could you please provide the steps to try it by my side?

Also, it is useful to know the silicon version that you are using.

Best regards,

Salas.