Merge pull request #1046 from iNavFlight/uninitialized-i2c-fix

Fix a bug with accessing the non-initialized I2C bus (backport to master)

Author: digitalentity

src/main/drivers/bus_i2c_stm32f10x.c

@@ -514,6 +514,10 @@ bool i2cWrite(I2CDevice device, uint8_t addr, uint8_t reg, uint8_t data)
 {
     static uint8_t writeBuf[1];
 
+    // Don't try to access the non-initialized device
+    if (!busState[device].initialized)
+        return false;
+
     // Set up write transaction
     writeBuf[0] = data;
 
@@ -533,6 +537,10 @@ bool i2cWrite(I2CDevice device, uint8_t addr, uint8_t reg, uint8_t data)
 
 bool i2cRead(I2CDevice device, uint8_t addr, uint8_t reg, uint8_t len, uint8_t* buf)
 {
+    // Don't try to access the non-initialized device
+    if (!busState[device].initialized)
+        return false;
+
     // Set up read transaction
     busState[device].addr = addr << 1;
     busState[device].reg = reg;

src/main/drivers/bus_i2c_stm32f30x.c

@@ -376,6 +376,10 @@ bool i2cWrite(I2CDevice device, uint8_t addr, uint8_t reg, uint8_t data)
 {
     static uint8_t writeBuf[1];
 
+    // Don't try to access the non-initialized device
+    if (!busState[device].initialized)
+        return false;
+
     // Set up write transaction
     writeBuf[0] = data;
 
@@ -395,6 +399,10 @@ bool i2cWrite(I2CDevice device, uint8_t addr, uint8_t reg, uint8_t data)
 
 bool i2cRead(I2CDevice device, uint8_t addr, uint8_t reg, uint8_t len, uint8_t* buf)
 {
+    // Don't try to access the non-initialized device
+    if (!busState[device].initialized)
+        return false;
+
     // Set up read transaction
     busState[device].addr = addr << 1;
     busState[device].reg = reg;