Hard Lockup

Hi friends, I use nano to do a easy application with some button control using python gpio. The application will start when boot automatically. Sometimes the system boot will fail, and I check the console(below picture), find out the hard lockup. Can somebody tell me what happen?
How can I know which IRQ occur error?

Thank you very much!

hello ward.tsai,

there’s watchdog timer to cause kernel panic, you may look into your kernel modifications to rule out the issues.
you may also check Flash Script Usage to use -k options for updating kernel partition.

Hi JerryChang,

Jetson version:

R32 (release), REVISION: 4.2, GCID: 20074772, BOARD: t210ref, EABI: aarch64, DATE: Thu Apr 9 01:22:12 UTC 2020

I have only modified the kernel for fix some issue of ath10k wifi driver, following this url .
Only change this file - hardware/nvidia/platform/t210/porg/kernel-dts/porg-platforms/tegra210-porg-pcie.dtsi.
Lines to remove:
/delete-property/ iommus;
/delete-property/ iommu-map;
/delete-property/ iommu-map-mask;

Is this modification will cause the hard lockup?
Thank you!

hello ward.tsai,

yes, there’re several devices working with iommu* property,
you may also access L4T sources and check the device tree sources.
for example,

Hi JerryChang,

Sorry, I’m a noob of linux kernel. I don’t know what these mean:
/delete-property/ iommus;
/delete-property/ iommu-map;
/delete-property/ iommu-map-mask;

Could you kindly tell me?
Thank you very much.

hello ward.tsai,

device tree (*.dtsi) files have create the node property to include the definitions, these nodes can also be delete by the /delete-property/ commands.
there’re several dtsi files being included for building the dtb file and flashing to the DTB partition.
you may have a quick way to disassembler the dtb file into text file for examination.
for example, $ dtc -I dtb -O dts -o output.txt tegra210-p3448-0000-p3449-0000-a02.dtb

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