From fad9210cb981172d1aa1f34f2c352446f8471a7d Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Thu, 23 Apr 2026 20:43:04 -0500
Subject: [PATCH] [mdns] Drop redundant USE_MDNS_EVENT_DRIVEN_POLLING guards in
 platform .cpp files
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The Python validator enforces that wifi or ethernet is configured on ESP8266/
RP2040, so USE_WIFI_IP_STATE_LISTENERS (or the ethernet equivalent) is always
requested in production, which always defines USE_MDNS_EVENT_DRIVEN_POLLING via
mdns_component.h's derivation. defines.h also declares it unconditionally for
static analysis. The #ifdef guards around start_polling_window_, setup()'s
listener subscription, and on_ip_state were dead code — a misconfiguration
should surface as a compile error, not silently strip out the method bodies.
---
 esphome/components/mdns/mdns_esp8266.cpp | 6 ------
 esphome/components/mdns/mdns_rp2040.cpp  | 4 ----
 2 files changed, 10 deletions(-)

diff --git a/esphome/components/mdns/mdns_esp8266.cpp b/esphome/components/mdns/mdns_esp8266.cpp
index 95137ea1164..3b9cfc65ffd 100644
--- a/esphome/components/mdns/mdns_esp8266.cpp
+++ b/esphome/components/mdns/mdns_esp8266.cpp
@@ -38,26 +38,21 @@ static void register_esp8266(MDNSComponent *, StaticVector<MDNSService, MDNS_SER
   }
 }
 
-#ifdef USE_MDNS_EVENT_DRIVEN_POLLING
 void MDNSComponent::start_polling_window_() {
   // uint32_t-ID set_interval/set_timeout already does atomic cancel-and-add.
   this->set_interval(MDNS_POLL_ID, MDNS_UPDATE_INTERVAL_MS, []() { MDNS.update(); });
   this->set_timeout(MDNS_POLL_STOP_ID, MDNS_POLL_WINDOW_MS, [this]() { this->cancel_interval(MDNS_POLL_ID); });
 }
-#endif
 
 void MDNSComponent::setup() {
   this->setup_buffers_and_register_(register_esp8266);
-#ifdef USE_MDNS_EVENT_DRIVEN_POLLING
   // LEAmDNS's own LwipIntf::statusChangeCB drives _restart() on netif changes; we just
   // arm the window around the initial probe/announce and each reconnect. Unconditional
   // here is safe: setup_priority::AFTER_CONNECTION guarantees the network is up.
   wifi::global_wifi_component->add_ip_state_listener(this);
   this->start_polling_window_();
-#endif
 }
 
-#ifdef USE_MDNS_EVENT_DRIVEN_POLLING
 void MDNSComponent::on_ip_state(const network::IPAddresses &ips, const network::IPAddress &,
                                 const network::IPAddress &) {
   // IP listener only fires on acquisition (not loss), so any notification is a fresh
@@ -66,7 +61,6 @@ void MDNSComponent::on_ip_state(const network::IPAddresses &ips, const network::
     this->start_polling_window_();
   }
 }
-#endif
 
 void MDNSComponent::on_shutdown() {
   MDNS.close();
diff --git a/esphome/components/mdns/mdns_rp2040.cpp b/esphome/components/mdns/mdns_rp2040.cpp
index f5848893a34..ece2bc5ace3 100644
--- a/esphome/components/mdns/mdns_rp2040.cpp
+++ b/esphome/components/mdns/mdns_rp2040.cpp
@@ -38,13 +38,11 @@ static void register_rp2040(MDNSComponent *, StaticVector<MDNSService, MDNS_SERV
   }
 }
 
-#ifdef USE_MDNS_EVENT_DRIVEN_POLLING
 void MDNSComponent::start_polling_window_() {
   // uint32_t-ID set_interval/set_timeout already does atomic cancel-and-add.
   this->set_interval(MDNS_POLL_ID, MDNS_UPDATE_INTERVAL_MS, []() { MDNS.update(); });
   this->set_timeout(MDNS_POLL_STOP_ID, MDNS_POLL_WINDOW_MS, [this]() { this->cancel_interval(MDNS_POLL_ID); });
 }
-#endif
 
 void MDNSComponent::setup() {
   // arduino-pico stubs out LwipIntf::stateUpCB (the netif status callback LEAmDNS uses
@@ -74,7 +72,6 @@ void MDNSComponent::setup() {
 #endif
 }
 
-#ifdef USE_MDNS_EVENT_DRIVEN_POLLING
 void MDNSComponent::on_ip_state(const network::IPAddresses &ips, const network::IPAddress &,
                                 const network::IPAddress &) {
   // Listener only fires on IP acquisition (not loss); every event is a fresh IP.
@@ -89,7 +86,6 @@ void MDNSComponent::on_ip_state(const network::IPAddresses &ips, const network::
   }
   this->start_polling_window_();
 }
-#endif
 
 void MDNSComponent::on_shutdown() {
   MDNS.close();