Interrupt errors using input only GPIO

[SuGlider]

Discussed in #11874

^{Originally posted by MeisterQ September 25, 2025}
Hello, im using Interrupts on esp32 and i always get the errors:

16:50:46.072 -> E (1714) gpio: gpio_pullup_en(78): GPIO number error (input-only E (1762) gpio: gpio_isr_handler_remove(568): GPIO isr service is not installed, call gpio_install_isr_service() first
16:50:46.118 -> E (1763) gpio: gpio_isr_handler_remove(568): GPIO isr service is not installed, call gpio_install_isr_service() first

This is my function where i call it

void fan()
{
  unsigned long currentMillis2 = millis();
  if (currentMillis2 - previousMillis2 >= interval2)
  {
    detachInterrupt(digitalPinToInterrupt(FAN1RPM));
    detachInterrupt(digitalPinToInterrupt(FAN2RPM));

    rpm1 = half_revolutions1 * 30;
    rpm2 = half_revolutions2 * 30;

    //Serial.print("Fan1: ");
    //Serial.println(rpm1);
    //Serial.print("Fan2: ");
    //Serial.println(rpm2);

    half_revolutions1 = 0;
    half_revolutions2 = 0;
    previousMillis2 = currentMillis2;

    attachInterrupt(digitalPinToInterrupt(FAN1RPM), rpm_fan1, RISING);
    attachInterrupt(digitalPinToInterrupt(FAN2RPM), rpm_fan2, RISING);
  }
}

Is there anything i can do to fix this?

Im using GPIO 34 ands 35 for interrupt with an external pullup resistor connected. The module is a esp-wroom-32.

If i comment all interrupt lines, the error is gone.

[SuGlider]

Not sure if this is expected. In general, I'd say that INPUT GPIO should be able to handle INT.
It needs investigation.

[P-R-O-C-H-Y]

This is not a bug. On ESP32, GPIO34–GPIO39 are input-only and do not have internal pull-up or pull-down resistors, so you cannot enable a pull-up on them using gpio_set_pull_mode() or similar software APIs.[ESP32 GPIO summary][ESP32 datasheet notes]

If you need a defined logic level on GPIO34 or GPIO35, you must add an external pull-up or pull-down resistor on your hardware. The error message is correct.