IMX6ULL: [ 75.326643] watchdog: watchdog0: watchdog did not stop! on Linux 6.1.1

[rprronad]

Dear Experts,

i.MX Processor: MCIMX6Y2CVM08AB

Kernal version: 6.1.1

I'm currently working on a custom System on Module (SOM) with an evaluation board (EVB) featuring the IMX6ULL Processor. I'm facing an issue with the watchdog configuration in the device tree source (dts) file. Our board (EVB) doesn't utilize the external pin assignment of the watchdog for triggering the RESET SWITCH. I need help triggering the RESET switch without assigning the external pin of the watchdog in the dts file.

I've referred to https://community.nxp.com/t5/i-MX-Processors/iMX6ULL-Watchdog-2-does-not-reset-system-on-Linux-5-4/t... this page but still encounter the same issue.

Below is the minicon console log:

[   75.326643] watchdog: watchdog0: watchdog did not stop!
[   75.454057] systemd-shutdown[1]: Syncing filesystems and block devices.
[   75.466793] systemd-shutdown[1]: Sending SIGTERM to remaining processes...
[   75.500037] systemd-journald[136]: Received SIGTERM from PID 1 (systemd-shutdow).
[   75.533967] systemd-shutdown[1]: Sending SIGKILL to remaining processes...
[   75.580073] systemd-shutdown[1]: Using hardware watchdog 'imx2+ watchdog', version 0, device /dev/watchdog
[   75.613192] systemd-shutdown[1]: Unmounting file systems.
[   75.629645] systemd-shutdown[1]: All filesystems unmounted.
[   75.641787] systemd-shutdown[1]: Deactivating swaps.
[   75.652640] systemd-shutdown[1]: All swaps deactivated.
[   75.663915] systemd-shutdown[1]: Detaching loop devices.
[   75.701770] systemd-shutdown[1]: All loop devices detached.
[   75.714008] systemd-shutdown[1]: Stopping MD devices.
[   75.726478] systemd-shutdown[1]: All MD devices stopped.
[   75.737972] systemd-shutdown[1]: Detaching DM devices.
[   75.750480] systemd-shutdown[1]: All DM devices detached.
[   75.762128] systemd-shutdown[1]: All filesystems, swaps, loop devices, MD devices and DM devices detached.
[   75.791880] systemd-shutdown[1]: Syncing filesystems and block devices.
[   75.802564] systemd-shutdown[1]: Rebooting.
[   75.820672] ci_hdrc ci_hdrc.1: remove, state 4
[   75.825248] usb usb1: USB disconnect, device number 1
[   75.832068] ci_hdrc ci_hdrc.1: USB bus 1 deregistered
[   75.852437] imx2-wdt 20bc000.watchdog: Device shutdown: Expect reboot!
[   75.860581] reboot: Restarting system

As per the above result, I've tried external pin assignment of watchdog1 in the dts file, but now it should work with the automatic (internal mode) watchdog configuration for the RESET switch.

Could someone help out with this issue?

Thanks in advance.

Best Regards,

Ravikumar

[rprronad]

Hello @Alejandro_Salas 

Thanks for your response.

In our dts file, The usage of watchdog node is:

&wdog1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_wdog>;
fsl,ext-reset-output;
status = "okay";
};

pinctrl_wdog: wdoggrp {
fsl,pins = <
MX6UL_PAD_LCD_RESET__WDOG1_WDOG_ANY 0x30b0
>;
};

Currently LCD_RESET used as WDOG_B signal right now. but

Could you confirm if there's an automatic software method for triggering the reset switch instead of using the hardware alternative method (as you mentioned: configuring the LCD_VSYNC pin as WDOG_B)? Additionally, How can the reset switch be held for a specified duration without employing a hardware method?

Thanks & Regards,
Ravikumar

[Alejandro_Salas · Accepted solution]

Hello @rprronad ,

In that case you referred, They are trying to use WDOG2, but WDOG2 is TZ:

You have to use hardware method. Configure  the LCD_VSYNC pin as WDOG_B.

Also, please share your dts file to see the WDOG1 configuration.

Best regards.

Salas.