2395354_en-US

[#1]

i.MX95 - Unable to perform the SOC reset from A55 core

Hello Experts,

I am working on i.MX95 and would like to perform the SOC reset (including M55 and M7 cores) from the A55 core.

With reference to section 18.2 in https://www.nxp.com/docs/en/user-guide/UG10163.pdf

CRRM also needs a cold reboot (reboot SoC) to trigger the mode switch, for example, from recovery
downloading to recovery installation. To meet it, we implement PSCI RESET2 in ATF, and use "reboot" rather
than "reset" in U-Boot for this SoC reset. The kernel also adds the imx-sm-reset driver to call PSCI RESET2
to ATF. User application needs to use the following syscall to trigger the board reset.

syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
       LINUX_REBOOT_CMD_RESTART2, "board_reset");

I have created a test application(In attachments) with this syscall included to trigger SOC reset from A55 core. However upon execution, it only resets A55 core and other M33 and M7 cores remain intact.

If someone has tried this before and reset the complete SOC, kindly let me know

Thanks in Advance !

BR,

Arun Kumar 

Re: i.MX95 - Unable to perform the SOC reset from A55 core

Hello,

When using the SCMI protocol to manage SoC regional resets, SM must handle the associated LP handshakes generated by the regional reset. In addition, some regional resets such as A55 have dependencies on each other. For example, issuing a A55Cx reset can only be issued in conjunction with an overall A55 regional (non-cooperative) reset.

Reset from bash using reboot command has the same behavior, if a complete SoC restart is required, including all processing domains, a watchdog-triggered reset or a PMIC-driven power cycle may be required.

Best regards.