Fix backward compatibility issue with len and dlc

src/modm/architecture/interface/can_message.hpp.in

@@ -25,13 +25,14 @@ namespace modm::can
 /// @ingroup modm_architecture_can
 struct Message
 {
-	inline Message(uint32_t inIdentifier = 0, uint8_t inDlc = 0) :
-		identifier(inIdentifier), flags(), length(inDlc)
+	inline Message(uint32_t inIdentifier = 0, uint8_t inLength = 0) :
+		identifier(inIdentifier), flags()
 	{
+        setLength(inLength);
 	}
 
-	inline Message(uint32_t inIdentifier, uint8_t inDlc, const uint64_t &inData, bool extended = false) :
-		Message(inIdentifier, inDlc)
+	inline Message(uint32_t inIdentifier, uint8_t inLength, const uint64_t &inData, bool extended = false) :
+		Message(inIdentifier, inLength)
 	{
 		flags.extended = extended;
 		const uint8_t *inDataB = reinterpret_cast<const uint8_t *>(&inData);
@@ -103,8 +104,10 @@ struct Message
 	setDataLengthCode(uint8_t inDlc)
 	{
 		while (dlcConversionTable[inDlc] > capacity) inDlc--;
+
 		dlc = inDlc;
 		length = dlcConversionTable[inDlc];
+		if (dlc > 8) setFlexibleData();
 	}
 
 	inline void
@@ -124,7 +127,7 @@ struct Message
 	inline uint8_t
 	getDataLengthCode() const
 	{
-		return length;
+		return dlc;
 	}
 
 public:
@@ -153,6 +156,7 @@ public:
 	operator == (const modm::can::Message& rhs) const
 	{
 		return ((this->identifier     == rhs.identifier) and
+				(this->dlc            == rhs.dlc)        and
 				(this->length         == rhs.length)     and
 				(this->flags.fd       == rhs.flags.fd)   and
 				(this->flags.brs      == rhs.flags.brs)  and
@@ -165,6 +169,7 @@ public:
 	operator = (const modm::can::Message& rhs)
 	{
 		this->identifier     = rhs.identifier;
+        this->dlc            = rhs.dlc;
 		this->length         = rhs.length;
 		this->flags.fd       = rhs.flags.fd;
 		this->flags.brs      = rhs.flags.brs;

src/modm/platform/can/stm32-fdcan/can.cpp.in

@@ -119,7 +119,7 @@ readMsg(modm::can::Message& message, uint8_t fifoIndex, uint8_t* filter_id, uint
 	}
 
 	const uint8_t dlcValue = MessageRam::RxDlc_t::get(rxHeader);
-	message.setLength(dlcValue);
+	message.setDataLengthCode(dlcValue);
 
 	// required for optimization in MessageRam::readData()
 	static_assert((std::size(decltype(message.data){}) % 4) == 0);