i.MX ProcessorsのトピックRe: i.MX6 watchdog: reboot on system halt

i.MX6 watchdog: reboot on system halt

morix — Tue, 09 Feb 2016 11:07:31 GMT

Hello,

I am currently working on a system based on i.MX6 Solo and I am experiencing a "weird" behavior...

Everytime I shutdown my Linux box (kernel 3.10.17) by typing "halt", then at the end (just before "Power down") the kernel dumps something like "imx2-wdt 20bc000.wdog: Device shutdown: Expect reboot!" and after a couple of minutes the board is restarted...

In my own opinion, if I halt the system on my own, then I want to keep it turned off, isn't it? Why the watchdog fires? Is there a way for avoiding that?

Thanks + regards,

/Morix

Re: i.MX6 watchdog: reboot on system halt

igorpadykov — Tue, 09 Feb 2016 13:02:49 GMT

Hi Moris

seems poweroff command should be used, as halting involves stopping cpu on the system

(note wdog can not be stopped).

Powering off involves sending an ACPI command to disconnect main power.

http://serverfault.com/questions/191537/shutdown-what-is-difference-between-power-off-and-halt

Best regards

igor

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Re: i.MX6 watchdog: reboot on system halt

morix — Tue, 09 Feb 2016 13:49:59 GMT

Hi Igor,

I've tried to do a "shutdown -h -P now" (shutdown man page told me that "-P" can only be used in connection with "-h") but that hasn't fixed my problem...

Again, after power down, the watchdog fires and the platform is restarted.

The only thing that has changed is that doing "shutdown -h -P now" the system is not cleanly shutdown: I mean the "/etc/init.d" scripts for terminating running processes are not called, and instead running processes are simply killed sending the TERM signal to them...

Any other ideas?

Thanks + regards,

/Morix

Re: i.MX6 watchdog: reboot on system halt

igorpadykov — Wed, 10 Feb 2016 00:24:51 GMT

Hi Morix

seems board restarts due to "AUTO ON" feature shown on p.19 spf-27392,

there is optional circuit for turning it off:

Schematics (1)

"Design files, including hardware schematics, Gerbers, and OrCAD files. (REV C5) "

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=RDIMX6SABREPLAT&fpsp=1&tab=Design_Tools_Tab

Best regards

igor

Re: i.MX6 watchdog: reboot on system halt

morix — Wed, 10 Feb 2016 06:35:40 GMT

Thanks Igor, I'll give it a try!

/Morix