From 0607e921cbc7a4f900b8ac88f417af9b3fffb3a0 Mon Sep 17 00:00:00 2001
From: bugobliterator <siddharthbharatpurohit@gmail.com>
Date: Wed, 1 Nov 2023 16:04:23 +1100
Subject: [PATCH] AP_Periph: solve a potential case where last_transmit_us can
 change inside irqs

---
 Tools/AP_Periph/can.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Tools/AP_Periph/can.cpp b/Tools/AP_Periph/can.cpp
index deadcd03f36f7..01adff69a5f60 100644
--- a/Tools/AP_Periph/can.cpp
+++ b/Tools/AP_Periph/can.cpp
@@ -1136,8 +1136,9 @@ void AP_Periph_FW::processTx(void)
                   active if it has had a successful transmit in the
                   last 2 seconds
                  */
-                const auto *stats = _ins.iface->get_statistics();
-                if (stats == nullptr || now_us - stats->last_transmit_us < 2000000UL) {
+                volatile const auto *stats = _ins.iface->get_statistics();
+                uint64_t last_transmit_us = stats->last_transmit_us;
+                if (stats == nullptr || AP_HAL::micros64() - last_transmit_us < 2000000UL) {
                     sent = false;
                 }
             } else {