From 1e66ecff607ab92fc4410c00f81e040035b6cc04 Mon Sep 17 00:00:00 2001
From: Alexander Balya <alexander.balya@gmail.com>
Date: Mon, 6 Jul 2026 17:21:24 +0200
Subject: [PATCH] Fix Ethernet MQTT reconnect handling (#10896)

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
---
 src/mesh/udp/UdpMulticastHandler.h |  6 ++++++
 src/mesh/wifi/WiFiAPClient.cpp     |  5 +++++
 src/mqtt/MQTT.cpp                  | 10 +++++++++-
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/mesh/udp/UdpMulticastHandler.h b/src/mesh/udp/UdpMulticastHandler.h
index 2cf718ec6..625dc008a 100644
--- a/src/mesh/udp/UdpMulticastHandler.h
+++ b/src/mesh/udp/UdpMulticastHandler.h
@@ -33,6 +33,8 @@ class UdpMulticastHandler final
 #if defined(ARCH_NRF52) || defined(ARCH_PORTDUINO)
             LOG_DEBUG("UDP Listening on IP: %u.%u.%u.%u:%u", udpIpAddress[0], udpIpAddress[1], udpIpAddress[2], udpIpAddress[3],
                       UDP_MULTICAST_DEFAUL_PORT);
+#elif defined(USE_WS5500) || defined(USE_CH390D)
+            LOG_DEBUG("UDP Listening on IP: %s", ETH.localIP().toString().c_str());
 #else
             LOG_DEBUG("UDP Listening on IP: %s", WiFi.localIP().toString().c_str());
 #endif
@@ -98,6 +100,10 @@ class UdpMulticastHandler final
         if (!isEthernetAvailable()) {
             return false;
         }
+#elif defined(USE_WS5500) || defined(USE_CH390D)
+        if (!ETH.connected()) {
+            return false;
+        }
 #elif !defined(ARCH_PORTDUINO)
         if (WiFi.status() != WL_CONNECTED) {
             return false;
diff --git a/src/mesh/wifi/WiFiAPClient.cpp b/src/mesh/wifi/WiFiAPClient.cpp
index 37258cd65..3d0f4baaa 100644
--- a/src/mesh/wifi/WiFiAPClient.cpp
+++ b/src/mesh/wifi/WiFiAPClient.cpp
@@ -563,6 +563,11 @@ static void WiFiEvent(WiFiEvent_t event)
         break;
     case ARDUINO_EVENT_ETH_DISCONNECTED:
         syslog.disable();
+#if HAS_UDP_MULTICAST
+        if (udpHandler) {
+            udpHandler->stop();
+        }
+#endif
         LOG_INFO("Ethernet disconnected");
         break;
     case ARDUINO_EVENT_ETH_GOT_IP:
diff --git a/src/mqtt/MQTT.cpp b/src/mqtt/MQTT.cpp
index 9c2acf5a4..1374ef189 100644
--- a/src/mqtt/MQTT.cpp
+++ b/src/mqtt/MQTT.cpp
@@ -470,8 +470,16 @@ void MQTT::reconnect()
             reconnectCount++;
             LOG_ERROR("Failed to contact MQTT server directly (%d/%d)", reconnectCount, reconnectMax);
             if (reconnectCount >= reconnectMax) {
+#if defined(USE_WS5500) || defined(USE_CH390D)
+                LOG_WARN("MQTT connect failed repeatedly; waiting for Ethernet reconnect");
+#else
                 needReconnect = true;
-                wifiReconnect->setIntervalFromNow(0);
+                if (wifiReconnect) {
+                    wifiReconnect->setIntervalFromNow(0);
+                } else {
+                    LOG_WARN("MQTT connect failed repeatedly, but WiFi reconnect is unavailable");
+                }
+#endif
                 reconnectCount = 0;
             }
 #endif