Fix LibreTiny ISR safety: use vTaskNotifyGiveFromISR in wake_loop_any_context, update stale comment

esphome/core/lwip_fast_select.c

@@ -63,12 +63,12 @@
 //
 // Shared state and safety rationale:
 //
-//   esphome_main_task_handle (TaskHandle_t, 4 bytes):
-//     Written once by main loop in init(). Read by TCP/IP thread (in callback)
-//     and background tasks (in wake).
-//     Safe: write-once-then-read pattern. Socket hooks may run before init(),
+//   esphome_main_task_handle (TaskHandle_t, 4 bytes, defined in main_task.c):
+//     Written once by main loop in Application::setup(). Read by TCP/IP thread
+//     (in callback) and background tasks (in wake).
+//     Safe: write-once-then-read pattern. Socket hooks may run before setup(),
 //     but the NULL check on esphome_main_task_handle in the callback provides correct
-//     degraded behavior — notifications are simply skipped until init() completes.
+//     degraded behavior — notifications are simply skipped until setup() completes.
 //
 //   s_original_callback (netconn_callback, 4-byte function pointer):
 //     Written by main loop in hook_socket() (only when NULL — set once).

esphome/core/wake.h

@@ -34,8 +34,15 @@ void wake_loop_isrsafe(int *px_higher_priority_task_woken);
 /// IRAM_ATTR entry point — defined in wake.cpp.
 void wake_loop_any_context();
 #else
-/// LibreTiny: no working IRAM_ATTR, no ISR callers.
-inline void wake_loop_any_context() { esphome_main_task_notify(); }
+/// LibreTiny: GPIO ISRs are real hardware interrupts, so use ISR-safe API.
+/// vTaskNotifyGiveFromISR is safe from both ISR and task context on ARM Cortex-M.
+inline void wake_loop_any_context() {
+  if (esphome_main_task_handle != NULL) {
+    BaseType_t xHigherPriorityTaskWoken = pdFALSE;
+    vTaskNotifyGiveFromISR(esphome_main_task_handle, &xHigherPriorityTaskWoken);
+    portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
+  }
+}
 #endif
 
 inline void wake_loop_threadsafe() { esphome_main_task_notify(); }