ESP32 Wi-Fi "bricked" for hours when internet connectivity fails, even after connectivity restored

[BetterAutomations]

Please update the binaries to ESP-IDF 4.2+. Without this upstream fix, if the internet connection is down it can "brick" Wi-Fi on devices for hours on a failure in internet connectivity. Even after connectivity is restored, or even if the device is power-cycled, it can still fail to connect to the router, or it can generate numerous wifi:esf_buf errors. After a few hours, the devices start working again.

The fix:
espressif/esp-idf@5a0124a

The discussion on the ESP-IDF Github:
espressif/esp-idf#5391

Once I upgraded to ESP-IDF 4.2 for my own custom firmware, this problem disappeared, as per the upstream fix.

Hardware used:

• ESP32-WROVER-E 16MB (Lolin D32 Pro)
• ESP32-WROVER-IE 8MB (ESP32_DevKitc_V4)

Firmwares used:

• esp32spiram-20220117-v1.18.bin
• Custom firmware based on v1.18

Steps to reproduce:

• Disconnect upstream modem connectivity but leave router online
• Attempt to connect to router using code below
• When it fails, unplug the ESP32 from power
• Reconnect internet, confirm connectivity with your laptop
• Plug in device and try again
• If it fails, unplug it for a few hours
• Confirm connectivity still good
• Should start working again

To resolve:

• Upgrade ESP-IDF to 4.2+
• Recompile firmware
• Flash to device

Code used:

import network
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('MYSSID', 'MYPASSPHRASE')
# Repeatedly paste this command several times until about 60 seconds goes by. Sometimes even when there is connectivity, connection is slow and this should eventually show an IP.
sta_if.ifconfig()

Errors shown:

E (83336) wifi:sta is connecting, return error
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: Wifi Internal Error

Or sometimes:

E (45979) wifi:esf_buf: t=2 l=76 max:32, alloc:32 no eb, TXQ_BLOCK=0
W (45979) wifi:alloc eb len=76 type=2 fail, heap:151108

W (45979) wifi:m f probe req l=0

E (46099) wifi:esf_buf: t=2 l=76 max:32, alloc:32 no eb, TXQ_BLOCK=0
W (46099) wifi:alloc eb len=76 type=2 fail, heap:151108

W (46099) wifi:m f probe req l=0

E (46229) wifi:esf_buf: t=2 l=76 max:32, alloc:32 no eb, TXQ_BLOCK=0
W (46229) wifi:alloc eb len=76 type=2 fail, heap:151108

W (46229) wifi:m f probe req l=0
...

[dpgeorge]

Please update the binaries to ESP-IDF 4.2+

The esp32 firmware available at https://micropython.org/download uses IDF v4.2.2 (or v4.4 for S2, S3, C3 variants). So I think they should be OK, they should include this fix?

[BetterAutomations]

Hmm. I know that when I switched my custom firmware from 4.0 to 4.2 the problem disappeared, and I had assumed that because the compilation instructions suggest to use 4.0.2 that the firmware at the download site had used 4.0.2. Perhaps at least update the README.md.

Are you able to reproduce the errors above using the firmware I mentioned? Perhaps there is another cause.