From 9013c15f4d42c2b428abe04d377c2f5bc9214047 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 7 Feb 2019 08:40:18 +1100
Subject: [PATCH] AP_Bootloader: fixed sys lock for timer

---
 Tools/AP_Bootloader/bl_protocol.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Tools/AP_Bootloader/bl_protocol.cpp b/Tools/AP_Bootloader/bl_protocol.cpp
index 63f467da95..d9017f63c4 100644
--- a/Tools/AP_Bootloader/bl_protocol.cpp
+++ b/Tools/AP_Bootloader/bl_protocol.cpp
@@ -130,9 +130,9 @@ volatile unsigned timer[NTIMERS];
  */
 static void sys_tick_handler(void *ctx)
 {
-    chSysLock();
+    chSysLockFromISR();
     chVTSetI(&systick_vt, chTimeMS2I(1), sys_tick_handler, nullptr);
-    chSysUnlock();
+    chSysUnlockFromISR();
     uint8_t i;
     for (i = 0; i < NTIMERS; i++)
         if (timer[i] > 0) {