imx6SoloX: internal reset issue

mchaplet — Tue, 30 Aug 2022 16:24:13 GMT

I noticed few issues regarding internal reset on imx6Solox:

Linux kernel is used. The imx2_wdt driver well writes WDE and WDA bits in WDT_WCR register to trigger internal reset signal and reboot MPU.

But on few products (9 for now), it sometimes doesn't reset at all.

I currently have access to 2 products reproducing continuously this issue between 10 and 500 reboots.

The most mysterious behavior is that Watchdog timer is started but doesn't trig reset neither. (I thought it was impossible to disable watchdog once started).

However, an "HW reset" (glitch on POR_B) seems to solve this issue. But this is not acceptable for our customers.

I saw that SoloX Sabre Reference design includes this note:

“Fix the SW reboot issue by togling WDOG_B to issue power reset (ENGR00338067).”

This issue doesn't seem to be referenced by any errata nor documentation excepting AN5161.

But we don't use PMIC on our various designs.

Can you explain what is this issue ?

Is this "SW reboot issue" is still present in last silicon version of SoloX ?

Is it also present in imx6ULL and imx8 family ?

Do you have any software workaround / recommandations ?

Re: imx6SoloX: internal reset issue

mchaplet — Wed, 07 Sep 2022 11:29:18 GMT

After few tests, I can confirm that the same Freeze issue happens also with WDOG3 and TemperatureSensor as reset sources.

To be clear, our current conclusion is that:

ALL internal reset sources are unreliable !

Can you confirm ?
Is there a way to simulate reset from software in Linux environment ? (something like loading Romboot and jumping to it ?)

i.MX ProcessorsのトピックRe: imx6SoloX: internal reset issue

imx6SoloX: internal reset issue

Re: imx6SoloX: internal reset issue