From a5fd60ec71aead28c63f33c85fbfbd23286eb50b Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Tue, 1 Aug 2023 17:06:28 +1000
Subject: [PATCH] AP_CANManager: fixed usage of read_locked

this didn't actually cause an issue, but is wrong
---
 libraries/AP_CANManager/AP_SLCANIface.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/AP_CANManager/AP_SLCANIface.cpp b/libraries/AP_CANManager/AP_SLCANIface.cpp
index c19e3c56d6..c635494ac6 100644
--- a/libraries/AP_CANManager/AP_SLCANIface.cpp
+++ b/libraries/AP_CANManager/AP_SLCANIface.cpp
@@ -722,7 +722,7 @@ int16_t SLCAN::CANIface::receive(AP_HAL::CANFrame& out_frame, uint64_t& rx_time,
         // flush bytes from port
         while (num_bytes--) {
             uint8_t b;
-            if (!_port->read_locked(&b, 1, _serial_lock_key)) {
+            if (_port->read_locked(&b, 1, _serial_lock_key) != 1) {
                 break;
             }
             addByte(b);