Industrial imx6q watchdog reboot failed

[ivychend]

Hi nxp community:

I am working on industial imx6q. DDR3 ic: IS43TR16256AL(industrial standard).

using downward command to kill watchdog daemon to make imx6q reboot

mount -o remount,rw / && mv /sbin/watchdogd /             #  android 4.4 debug console operation
kill -9 `ps | grep watchdogd | busybox awk '{print $2}'`    # kill /sbin/watchdogd to let /dev/watchdog go

echo 1 > /dev/watchdog                                                   # qt 4.8.5 system， wait for a short time, imx6q reboot

then, imx6q reboot, but always stack at kernel. Can not run into system, no matter android or qt

error information in imx6q-watchdog-reboot-failed.txt

[igorpadykov]

Hi Jeff

one can check if watchdog reboot toggle pmic pwron signal as on p.21

spf-27392 i.MX6Q Sabre SD schematic

https://www.nxp.com/webapp/Download?colCode=iMX6Q-SABRE-SDB-DESIGNFILES&appType=license 

Best regards
igor
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[ivychend]

Hi ignore

Using the same image of imx6q, commercial version imx6q watchdog works fine, industrial verison not

[igorpadykov]

so had you checked if reset will toggle pmic pwron signal ?

Without that behaviour may be random.

[ivychend]

I had checked pmic pwron for many times and reset did not affect the pmic pwron pin. 

Does WDOG_B(gpio_1) pin need to be toggled by watchdog driver(drivers/watchdog/imx2_wdt.c). From arch/arm/mach-mx6/board-mx6q_sabresd.h, I can see that gpio_1 define MX6Q_PAD_GPIO_1__WDOG2_WDOG_B. But imx2_wdt.c and board-mx6q_sabresd.c never toggle this pin.

Referring to imx6q datasheet, I found out that WDOG1_B is one of DISP0_DAT8、GPIO_9 and SD1_DAT2 and
WDOG2_B is one of DISP0_DAT9、GPIO_1 and SD1_DAT3. Imx6q linux 3.0.35 register watchdog 0 by default from arch/arm/mach-mx6/board-mx6q_sabresd.c (imx6q_add_imx2_wdt(0, NULL);), should this be ok? 

[igorpadykov]

>I had checked pmic pwron for many times and reset did not affect the pmic pwron pin. 

then may be suggested to implement solution when wdog toggles pwron as implemented

on Sabre SD schematic spf-27392 p.21 (U507)

Design files, including hardware schematics, Gerbers, and OrCAD files for i.MX 6Quad (i.MX 6Dual emu...

without such solution there is no board guaranteed reset.

Best regards
igor

[ivychend]

Hi igor

Had double checked the schematic. We had the same design with the schematic you offered. 

I think you misunderstood my words. The board can reset by watchdog trigger,  but can not run into system. The board cashed in kernel from the log file uploaded you can see. Can not find what is the reason

Best regards

jeff

[ivychend]

Hi igor

Have checked pmic pwron pin, was stable high and up to 2.9v form watchdog reboot to kernel error. Is it another reason lead to the kernel crash.

Any help would be appricated

Best regards

Jeff

[ivychend]

By the way, ddr pass the ddr test. And imx6q can run into system when using reboot key or running command reboot on debug console. Just watchdog reboot not works