From afaed41d6ed3327f2e6ce02aea597bc3c2187570 Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Thu, 23 Jan 2025 19:10:48 +1100
Subject: [PATCH] AP_Motors: clamp max-num-motors to num-servo-channels

---
 libraries/AP_Motors/AP_Motors_Class.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libraries/AP_Motors/AP_Motors_Class.h b/libraries/AP_Motors/AP_Motors_Class.h
index 775d073db3..58f45a7301 100644
--- a/libraries/AP_Motors/AP_Motors_Class.h
+++ b/libraries/AP_Motors/AP_Motors_Class.h
@@ -6,6 +6,7 @@
 #include <Filter/DerivativeFilter.h>
 #include <GCS_MAVLink/GCS_MAVLink.h>
 #include <AP_Logger/AP_Logger_config.h>
+#include <SRV_Channel/SRV_Channel_config.h>
 
 // offsets for motors in motor_out and _motor_filtered arrays
 #define AP_MOTORS_MOT_1 0U
@@ -47,6 +48,12 @@
 #else
 #define AP_MOTORS_MAX_NUM_MOTORS 12
 #endif
+
+// doesn't make sense to have more motors than servo channels, so clamp:
+#if NUM_SERVO_CHANNELS < AP_MOTORS_MAX_NUM_MOTORS
+#undef AP_MOTORS_MAX_NUM_MOTORS
+#define AP_MOTORS_MAX_NUM_MOTORS NUM_SERVO_CHANNELS
+#endif
 #endif
 
 #ifndef AP_MOTORS_FRAME_DEFAULT_ENABLED