Serial port split data

[ado130]

Hello,
I'm using MCU from TI MSP430FR with FTDI FT230.
Code in QT project to receive data from COM port:

connect(m_serialPort, &QSerialPort::readyRead, this, &TokozSerial::HandleReadyRead);
 
 
void TokozSerial::HandleReadyRead()
{    
    if(m_serialPort->bytesAvailable() > 0)
    {
        while (!m_serialPort->atEnd())
        {
            m_readData.append(m_serialPort->readAll());
        }
        HandleTimeout();
    }
}
 
void TokozSerial::HandleTimeout()
{
    m_serialPort->clear();
    qDebug() << "RawData" << m_readData;
    connect(this, &TokozSerial::HandleReady, gp_protocolUart, &ProtocolUart::HandleReady);
    emit HandleReady(m_readData);
    disconnect(this, &TokozSerial::HandleReady, gp_protocolUart, &ProtocolUart::HandleReady);
    disconnect(this, &TokozSerial::HandleReady, 0, 0);
    m_readData.clear();
}

connect(m_serialPort, &QSerialPort::readyRead, this, &TokozSerial::HandleReadyRead);


void TokozSerial::HandleReadyRead()
{    
    if(m_serialPort->bytesAvailable() > 0)
    {
        while (!m_serialPort->atEnd())
        {
            m_readData.append(m_serialPort->readAll());
        }
        HandleTimeout();
    }
}

void TokozSerial::HandleTimeout()
{
    m_serialPort->clear();
    qDebug() << "RawData" << m_readData;
    connect(this, &TokozSerial::HandleReady, gp_protocolUart, &ProtocolUart::HandleReady);
    emit HandleReady(m_readData);
    disconnect(this, &TokozSerial::HandleReady, gp_protocolUart, &ProtocolUart::HandleReady);
    disconnect(this, &TokozSerial::HandleReady, 0, 0);
    m_readData.clear();
}

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In HandleReady I parse this data so I think it's not necessary for this problem.
My problem is that eg. every 5th or 10th (sometimes) I get two packets instead of one.
Example:
MCU send: "\xA1\x00\x00\x01\x81\xDC\xD6"
I get: "\xA1\x00\x00\x01" and then "\x81\xDC\xD6 -- HandleReadyRead called twotimes. I know that together it is correct, but I think this is not working correctly.
It's not always the same. Sometimes I get first 2 bytes, then 5, or 1-6, 6-1 ...


Thanks for any advice.