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IMX6Q+PF100 PMIC reboot failed using hw wdog2

Question asked by May Queen on Jul 10, 2017
Latest reply on Jul 11, 2017 by May Queen

Hello All:

OS: Android 7.1

I refer Sabresd board and design a new board, but I have a big issue now: cannot reboot system, it will hangs before start u-boot.


For the hardware part:
1. I almost copy from sabresd board for PMIC relative circuit including power button, and the wdog2 pin also the same - GPIO_1, but when I issue reboot command, I observe the behavior using scope, the wdog2 is really pull lo and hi once but hardware has no any reset action...
I doubt maybe I use 2 5V regulators and 1 3.3V regulator from CPU
NANDF_CLE, NANDF_WP_B, and NANDF_RB0, maybe I need to pull lo first before reboot? but it doesn't make sense..


For the software part:
1. my dts is also follow sabresd:
linux-imx/imx6qdl-pistachio.dtsi at nutsboard_nxp_4.1.15_2.0.0_ga · nutsboard/linux-imx · GitHub 
maybe the gpc need to set ldo-bypass=0, but I also tried, and I also use gateworks patch to modify arch/arm/mach-imx/imx2-wdt.c, but still hangs...


2. because I have no more money to make a new board, I have a workaround way to force do soft reset only, and I refer this patch:
[RFC] imx6: Fix reboot routine for boards using WDOG2 as reset. 

it works but sometime still reboot hang or "random hangs when reboot success (hangs on u-boot always)", I loss some keys?

hope somebody can give me some comments, I don't want to my customers disappoint for this issue...

Thank you so much!