iMX6 Watchdog active, but resets irregularly in Linux

[erezsteinberg]

Hello all,

On a system with iMX6DL, WDOG1 is activated in U-Boot.

If U-Boot hangs, or Linux hangs during boot, the watchdog resets the system as expected.

However, if Linux boots, the watchdog does not cause a system reset on time.   It may take minutes, and then at some random time the system would reset.

Looking at the watchdog registers:

   Memory mapped at address 0x76f53000.

   Read at address  0x020BC000 (0x76f53000): 0x779F

Timeout is set to 60 seconds, and watchdog is enabled.

What might be the reason for such behavior?

Any suggestions how to debug this?

Regards,

Erez

[bandarulavanya]

Hi all ,

Can you please tell me how to enable watchdog timer in u boot for 2014 kernel version.

Thanks ,

Lavanya

[igorpadykov · Accepted solution]

Hi Erez

one can check WDOGx_WCR WDW or WDZST bit - Watchdog Disable for Wait

or low-power modes. These bit determines the operation of WDOG during Low Power WAIT mode.

Best regards

igor

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[erezsteinberg]

Thanks Igor,

The problem was due to the WDW bit in the watchdog configuration register.  The watchdog driver in U-Boot automatically sets it.

In Linux, the processor is place in WAIT mode whenever it is idle.  This causes the watchdog to suspend.  Setting WDW=0 resolves this issue.

Regards,

Erez