From eaa68f32e3277738467dc869d8e79a2537a41818 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Sat, 10 Dec 2016 08:15:11 +1100
Subject: [PATCH] AP_Param: avoid a notify if value is already correct

---
 libraries/AP_Param/AP_Param.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libraries/AP_Param/AP_Param.h b/libraries/AP_Param/AP_Param.h
index f5568d9a4e..5fa05bb3d1 100644
--- a/libraries/AP_Param/AP_Param.h
+++ b/libraries/AP_Param/AP_Param.h
@@ -536,8 +536,10 @@ public:
     /// Value setter - set value, tell GCS
     ///
     void set_and_notify(const T &v) {
-        set(v);
-        notify();
+        if (v != _value) {
+            set(v);
+            notify();
+        }
     }
 
     /// Combined set and save