From c0b8f2952cb3683d143b0aa2d39188e8b0a3d778 Mon Sep 17 00:00:00 2001
From: Daniel Agar <daniel@agar.ca>
Date: Fri, 23 Apr 2021 13:44:59 -0400
Subject: [PATCH] parameters: param_get_default_value avoid locking if value is
 static default

---
 src/lib/parameters/parameters.cpp | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/src/lib/parameters/parameters.cpp b/src/lib/parameters/parameters.cpp
index add193b0cb..ee3e950eb4 100644
--- a/src/lib/parameters/parameters.cpp
+++ b/src/lib/parameters/parameters.cpp
@@ -559,9 +559,30 @@ param_get_default_value_internal(param_t param, void *default_val)
 int
 param_get_default_value(param_t param, void *default_val)
 {
-	param_lock_reader();
-	int ret = param_get_default_value_internal(param, default_val);
-	param_unlock_reader();
+	if (!handle_in_range(param)) {
+		return PX4_ERROR;
+	}
+
+	int ret = 0;
+
+	if (!params_custom_default[param]) {
+		// return static default value
+		switch (param_type(param)) {
+		case PARAM_TYPE_INT32:
+			memcpy(default_val, &px4::parameters[param].val.i, sizeof(px4::parameters[param].val.i));
+			return PX4_OK;
+
+		case PARAM_TYPE_FLOAT:
+			memcpy(default_val, &px4::parameters[param].val.f, sizeof(px4::parameters[param].val.f));
+			return PX4_OK;
+		}
+
+	} else {
+		param_lock_reader();
+		ret = param_get_default_value_internal(param, default_val);
+		param_unlock_reader();
+	}
+
 	return ret;
 }