System Reboots Automatically with PMC Reset Source: BCCPLEXWDT

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
1

Title: System Reboots Automatically with PMC Reset Source: BCCPLEXWDT

Message:

Hello,

I am experiencing an issue where my system reboots automatically, and the following log is observed after the reboot:

Jan  5 12:13:55 tegra-ubuntu kernel: [    0.985776] tegra-pmc c360000.pmc: scratch reg offset dts data not present
Jan  5 12:13:55 tegra-ubuntu kernel: [    0.985803] tegra-pmc: ### PMC reset source: BCCPLEXWDT
Jan  5 12:13:55 tegra-ubuntu kernel: [    0.985845] tegra-pmc: ### PMC reset level: L1
Jan  5 12:13:55 tegra-ubuntu kernel: [    0.985857] tegra-pmc: ### PMC reset status reg: 0x9
Jan  5 12:13:55 tegra-ubuntu kernel: [    0.985994] tegra-pmc: PMC Prod config success

I would like clarification on the following:

  1. PMC reset status register (0x9): What does this register value represent?
  2. BCCPLEXWDT: As far as I know, this corresponds to TEGRA_DENVER_WATCHDOG. Could you confirm if this is correct and explain its significance?

For reference, my SOM is AGX Xavier, and I am using JetPack 5.1.2 with L4T 35.4.1.

Thank you for your support!

3

Hi hyunjin.chung0619,

Are you using the devkit or custom board for AGX Xavier?

It seems the reset is caused from watchdog.
Is there any hang issue before reboot?
Please share the full serial console log before and after reboot.

Have you also verified with the latest JP5.1.4(R35.6.0)?

4

I am using a custom board with the AGX Xavier, and I have also reproduced the issue on the devkit.

The system experiences a freeze before rebooting. I have also verified this behavior with the latest JetPack 5.1.4 (R35.6.0).

When using a DC power adapter, this issue does not occur. However, when power is supplied by a battery, the issue can be consistently reproduced. I would like to understand whether this behavior is related to the power supply.

Could you please provide clarification on the following points? Unfortunately, I could not find relevant documentation to refer to:

  1. PMC Reset Status Register (0x9): What does the value of this register represent?
  2. BCCPLEXWDT:* As far as I understand, this corresponds to TEGRA_DENVER_WATCHDOG. Could you confirm if this is correct and explain its significance?
5

Is there any log available to be shared at this moment?

Does your battery have the similar power output as DC power adapter?
(i.e. what’s their voltage and current?)

For the pmc driver, you can just refer to kernel/kernel-5.10/drivers/soc/tegra/pmc.c for details.