No emitted readyRead() if dataErrorPolicy != QSerialPort::IgnorePolicy and data present in system

 
Initialization:

...
QSerialPort     sport;
connect(&sport, SIGNAL(readyRead()), this, SLOT(portReadyRead()));
connect(&sport, SIGNAL(error(QSerialPort::SerialPortError)), this, SLOT(portError(QSerialPort::SerialPortError)));

cfg_portname = "COM1";
cfg_baudrete = QSerialPort::Baud9600;
cfg_databits = QSerialPort::Data8;
cfg_parity = QSerialPort::NoParity;
cfg_stopbits = QSerialPort::OneStop;
cfg_errorpolicy = QSerialPort::SkipPolicy; // <--
cfg_flowcontrol = QSerialPort::NoFlowControl;

sport.setPortName(cfg_portname);
sport.open(QIODevice::ReadWrite);
sport.setBaudRate(cfg_baudrete);
sport.setDataBits(cfg_databits);
sport.setParity(cfg_parity);
sport.setStopBits(cfg_stopbits);
sport.setDataErrorPolicy(cfg_errorpolicy);
sport.setFlowControl(cfg_flowcontrol);
...

SLOT:
void MbSerialPort::portReadyRead()
{
    //data_recv.append(sport.readAll());
    
    while (!sport.atEnd())
        data_recv.append(sport.read(100));
    emit devRecvPacket(data_recv);
    qDebug() << "INFO: MbSerialPort::portReadyRead() RECV: " << data_recv.toHex();    
    qDebug() << "INFO: error = " << sport.error() << " " << sport.errorString();

}

qserialport_win.cpp: /line 630/

bool QSerialPortPrivate::startAsyncRead()
{
    DWORD bytesToRead = policy == QSerialPort::IgnorePolicy ? ReadChunkSize : 1;
    ...
}