From 145cd2b3d77f32f623e45303cb3403afac80a2fb Mon Sep 17 00:00:00 2001
From: Florian <1technophile@users.noreply.github.com>
Date: Thu, 6 Apr 2023 15:10:39 -0500
Subject: [PATCH] [BT] Application level Watchdog Timer to avoid scan_evt
 timeout

Implement a BLE scan watchdog to bypass the problem related to the BLE scan hang scan_evt timeout
This is a bypass solution to espressif/arduino-esp32#5860
The watchdog will restart the ESP if no new BLE messages has been added to the queue following:

checked every 120s
if we are after the last BLE message time + the BLE scan interval for passive
if the process is not locked by an OTA update or other operation
We restart the ESP
We also remove the WDT0 enable and disable functions.
---
 main/ZgatewayBT.ino | 19 +++++++++++++++++--
 main/main.ino       |  1 +
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/main/ZgatewayBT.ino b/main/ZgatewayBT.ino
index e722e32892..ea6af723df 100644
--- a/main/ZgatewayBT.ino
+++ b/main/ZgatewayBT.ino
@@ -101,6 +101,23 @@ void BTConfig_init() {
   BTConfig.presenceAwayTimer = PresenceAwayTimer;
 }
 
+// Watchdog, if there was no change of btQueueLengthSum for 5 minutes, restart ESP
+void btScanWDG() {
+  static unsigned long previousbtQueueLengthSum = 0;
+  static unsigned long lastBtMsgTime = 0;
+  unsigned long now = millis();
+  if (!ProcessLock &&
+      previousbtQueueLengthSum == btQueueLengthSum &&
+      btQueueLengthSum != 0 &&
+      (now - lastBtMsgTime > BTConfig.BLEinterval)) {
+    Log.error(F("BLE Scan watchdog triggered at : %ds" CR), lastBtMsgTime / 1000);
+    ESPRestart();
+  } else {
+    previousbtQueueLengthSum = btQueueLengthSum;
+    lastBtMsgTime = now;
+  }
+}
+
 unsigned long timeBetweenConnect = 0;
 unsigned long timeBetweenActive = 0;
 
@@ -707,7 +724,6 @@ void BLEscan() {
   while (uxQueueMessagesWaiting(BLEQueue)) {
     yield();
   }
-  disableCore0WDT();
   Log.notice(F("Scan begin" CR));
   BLEScan* pBLEScan = BLEDevice::getScan();
   MyAdvertisedDeviceCallbacks myCallbacks;
@@ -723,7 +739,6 @@ void BLEscan() {
   BLEScanResults foundDevices = pBLEScan->start(BTConfig.scanDuration / 1000, false);
   scanCount++;
   Log.notice(F("Found %d devices, scan number %d end" CR), foundDevices.getCount(), scanCount);
-  enableCore0WDT();
   Log.trace(F("Process BLE stack free: %u" CR), uxTaskGetStackHighWaterMark(xProcBLETaskHandle));
 }
 
diff --git a/main/main.ino b/main/main.ino
index d7dbcbec64..3684af73c3 100644
--- a/main/main.ino
+++ b/main/main.ino
@@ -1617,6 +1617,7 @@ void loop() {
         stateMeasures();
 #  ifdef ZgatewayBT
         stateBTMeasures(false);
+        btScanWDG();
 #  endif
 #  ifdef ZactuatorONOFF
         stateONOFFMeasures();