From cbb3c8f08792624dc0763b33e6592294d6926cb7 Mon Sep 17 00:00:00 2001
From: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
Date: Tue, 21 Jul 2026 11:57:49 +1200
Subject: [PATCH] [esp32_hosted] Mark esp_now shim recv/send callback pointers
 volatile

They are written from the main loop and read from the esp-hosted RX thread;
volatile matches the treatment of the g_resp_* globals and makes the
cross-thread visibility intent explicit (per review).
---
 esphome/components/esp32_hosted/esp_now_hosted.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/esphome/components/esp32_hosted/esp_now_hosted.cpp b/esphome/components/esp32_hosted/esp_now_hosted.cpp
index 131322f4e6..d9590c8f85 100644
--- a/esphome/components/esp32_hosted/esp_now_hosted.cpp
+++ b/esphome/components/esp32_hosted/esp_now_hosted.cpp
@@ -61,8 +61,12 @@ volatile int32_t g_resp_status = 0;
 uint8_t g_resp_ret[16];
 volatile uint16_t g_resp_ret_len = 0;
 
-esp_now_recv_cb_t g_recv_cb = nullptr;
-esp_now_send_cb_t g_send_cb = nullptr;
+// Written from the main loop (register/unregister/deinit), read from the
+// esp-hosted RX thread (on_recv/on_send). volatile for the same reason the
+// g_resp_* globals are: force the RX thread to observe an updated pointer
+// (e.g. a nulling by esp_now_deinit) rather than a cached one.
+volatile esp_now_recv_cb_t g_recv_cb = nullptr;
+volatile esp_now_send_cb_t g_send_cb = nullptr;
 
 // ── CustomRpc event handlers (run on the esp-hosted RPC RX thread) ──────────
 // Keep them short and non-blocking. In particular they MUST NOT call back into