From fb38cf37fdad543e11c28d48eb9f2376848f90b8 Mon Sep 17 00:00:00 2001
From: MrKevinWeiss <weiss.kevin604@gmail.com>
Date: Wed, 14 Aug 2019 16:26:22 +0200
Subject: [PATCH] cpu/stm32: Fix read bytes flag for i2c_2

This commit stops a repeated start read which causes slave bus lockup
When trying to do a repeaded start i2c_read_bytes it returns -EOPNOTSUPP error
---
 cpu/stm32_common/periph/i2c_2.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/cpu/stm32_common/periph/i2c_2.c b/cpu/stm32_common/periph/i2c_2.c
index 7c1b38ddef..34fd0fd41e 100644
--- a/cpu/stm32_common/periph/i2c_2.c
+++ b/cpu/stm32_common/periph/i2c_2.c
@@ -218,6 +218,10 @@ int i2c_read_bytes(i2c_t dev, uint16_t address, void *data, size_t length,
     I2C_TypeDef *i2c = i2c_config[dev].dev;
     DEBUG("[i2c] read_bytes: Starting\n");
 
+    /* Do not support repeated start reading */
+    if ((i2c->SR2 & I2C_SR2_BUSY) && !(flags & I2C_NOSTART)) {
+        return -EOPNOTSUPP;
+    }
     int ret = _start(i2c, (address << 1) | I2C_FLAG_READ, flags, length);
     if (ret < 0) {
         if (ret == -ETIMEDOUT) {