Disabling Core0WDT in SPIFFS.format() might be the wrong WDT

[Bascy]

Board

ESP32 Dev Module

Device Description

Propriety board, based on ESP32 chip

Hardware Configuration

not relevant

Version

latest master (checkout manually)

IDE Name

VSCode with PlatformIO and pioArduino platform

Operating System

Windows 11

Flash frequency

40 Mhz

PSRAM enabled

no

Upload speed

460800

Description

In our factory-firmware version of the firware we call SPIFFS.format() in a pretty early stage of the setup(). This causes a very large number of E (28769) task_wdt: esp_task_wdt_reset(705): task not found errors to occur, before the setup continues as normal.

This is caused by the disableCore0WDT() call in SPIFFS.format().

Question 1: Why is this error occuring?
Question 2: Why is it necessary to disable the watchdog of the other cores idle task, as setup() is always running on core1?
Question 3: What if I have a task running on Core 0 that calls SPIFFS.format(), shouldnt that task disable the core1 Idle watchdog then?

Sketch

void setup() {
  Serial.begin(576000);
  Serial.println("Starting...");
  SPIFFS.begin(true);

  #ifdef COMPILE_FACTORY_FIRMWARE
  SPIFFS.format();
  #endif
...

Debug Message

E (28766) task_wdt: esp_task_wdt_reset(705): task not found
E (28767) task_wdt: esp_task_wdt_reset(705): task not found
E (28768) task_wdt: esp_task_wdt_reset(705): task not found
E (28769) task_wdt: esp_task_wdt_reset(705): task not found
E (28770) task_wdt: esp_task_wdt_reset(705): task not found
E (28771) task_wdt: esp_task_wdt_reset(705): task not found
E (28772) task_wdt: esp_task_wdt_reset(705): task not found
E (28773) task_wdt: esp_task_wdt_reset(705): task not found
E (28774) task_wdt: esp_task_wdt_reset(705): task not found
E (28775) task_wdt: esp_task_wdt_reset(705): task not found

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[lbernstone]

It is disabling the idle timer. While core1 is busy, it isn't feeding the idle timer on core 0, which causes the watchdog to fire.
The error is there because older versions of the IDF did not have any method to check the wdt status. That should be fixed with the latest PR.

[Bascy]

I am using the latest version of disableCore0WDT() with the boolean return value, and it is still giving me the error.
pioarduino 53.03.13, using Arduino 3.1.3

Also I still do not understand how this can be correct if you are calling SPIFFS.format() from core 0.

In the meantime I have learned why core0 idle warchdog might get triggered when formatting SPIFFS on core1, its because SPIFFS is a shared resource between the cores and prolonged acces could thus prevent core0 from firing idle task every now. (This is just to remind myself of this)

[me-no-dev]

The logic is: Core 1 WDT is OFF in Arduino, Core 0 WDT is ON. Disable Core 0 WDT while formatting to prevent WDT restarts. On single-core chips, WDT is disabled in Arduino, so the code should not do anything. We will look into the task not found error and try to fix it.

[Bascy]

@me-no-dev Thanks for the explanation. I didn't know that Core 1 WDT was switched off in Arduino.
Hope you will find the cause of the error

[lbernstone]

@me-no-dev I think it is the loopWDT that generates these errors, but I can't really see how to disable it during the format.