From b30f3697d29751dde3e221bc8d43204854a72b63 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Tue, 27 Aug 2019 07:59:21 +1000
Subject: [PATCH] HAL_ChibiOS: fixed build without ISR limit

---
 libraries/AP_HAL_ChibiOS/I2CDevice.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libraries/AP_HAL_ChibiOS/I2CDevice.cpp b/libraries/AP_HAL_ChibiOS/I2CDevice.cpp
index b289edb3e7..f3ca77aade 100644
--- a/libraries/AP_HAL_ChibiOS/I2CDevice.cpp
+++ b/libraries/AP_HAL_ChibiOS/I2CDevice.cpp
@@ -284,8 +284,10 @@ bool I2CDevice::_transfer(const uint8_t *send, uint32_t send_len,
             break;
         }
 
+#ifdef STM32_I2C_ISR_LIMIT
         AP_HAL::Util::PersistentData &pd = hal.util->persistent_data;
         pd.i2c_isr_count += I2CD[bus.busnum].i2c->isr_count;
+#endif
 
         if (ret == MSG_OK) {
             bus.bouncebuffer_finish(send, recv, recv_len);