From daf3f4d2f1b840c1ac9032e7b995b77dbb107b89 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Tue, 28 Apr 2026 10:41:17 -0500
Subject: [PATCH] [core] wakeable_delay: yield on already-woken fast path
 (ESP8266, RP2040) (#16045)

---
 esphome/core/wake/wake_esp8266.h  | 4 ++++
 esphome/core/wake/wake_rp2040.cpp | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/esphome/core/wake/wake_esp8266.h b/esphome/core/wake/wake_esp8266.h
index 80cd61035b..7eaaae5293 100644
--- a/esphome/core/wake/wake_esp8266.h
+++ b/esphome/core/wake/wake_esp8266.h
@@ -36,6 +36,10 @@ inline void ESPHOME_ALWAYS_INLINE wakeable_delay(uint32_t ms) {
   }
   if (g_main_loop_woke) {
     g_main_loop_woke = false;
+    // Yield even on the already-woken fast path so callers in tight loops
+    // (e.g. lwIP raw TCP wait_for_data_) make forward progress when ISRs
+    // keep re-setting g_main_loop_woke between iterations.
+    delay(0);
     return;
   }
   esp_delay(ms, []() { return !g_main_loop_woke; });
diff --git a/esphome/core/wake/wake_rp2040.cpp b/esphome/core/wake/wake_rp2040.cpp
index b18248dbd2..bdcbb1ad00 100644
--- a/esphome/core/wake/wake_rp2040.cpp
+++ b/esphome/core/wake/wake_rp2040.cpp
@@ -36,6 +36,10 @@ void wakeable_delay(uint32_t ms) {
   }
   if (g_main_loop_woke) {
     g_main_loop_woke = false;
+    // Yield even on the already-woken fast path so callers in tight loops
+    // (e.g. lwIP raw TCP wait_for_data_) make forward progress when async
+    // wakes keep re-setting g_main_loop_woke between iterations.
+    yield();
     return;
   }
   s_delay_expired = false;