BLE IRQ crash when thread is disabled

[shariltumin]

There is a BLE problem on ESP32 when it is compiled with THREAD and THREAD_GIL disabled in mpconfigport.h.

...
#define MICROPY_PY_THREAD                   (0)
#define MICROPY_PY_THREAD_GIL               (0)
#define MICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS_WITH_INTERLOCK (0)
...

The test firmware, MicroPython v1.26.0-preview.82.gae6062a45, was compiled with esp-idf-541

Test script (test.py):

import bluetooth
ble = bluetooth.BLE()
ble.active(True)
def ble_irq(event, data):
    print('IRQ Data:', event, data)
 
ble.irq(ble_irq)
ble.gap_scan(1000, 30000, 30000)

resulted in a crash:

MicroPython v1.26.0-preview.82.gae6062a45.kaki5 on 2025-05-23; Generic ESP32 module with ESP32
Type "help()" for more information.
>>> import test
>>> Unhandled exception in IRQ callback handler
NLR jump failed, val=0x3ffd17f0
ets Jun  8 2016 00:22:57

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:4112
load:0x40078000,len:15084
load:0x40080400,len:4
load:0x40080404,len:3332
entry 0x400805ac

The test was successful when run with the thread-enabled firmware.

[jonnor]

Interesting! Are you able to pinpoint where the crash comes from, and a proposal for how to fix it?

[shariltumin]

For the ESP32, MICROPY_NLR_SETJMP is enabled in the mpconfigport.h file.

...
#if CONFIG_IDF_TARGET_ARCH_XTENSA
#define MICROPY_NLR_SETJMP                  (1)
#endif
....

This flag is used by py/nlr.h and py/nlrsetjmp.c, but I don't know how disabling or enabling threads affects the runtime IRQ for BLE. Perhaps others have a better understanding of how MicroPython works.