1 files changed, 9 insertions, 5 deletions
diff --git a/src/serialport/qserialport_win.cpp b/src/serialport/qserialport_win.cpp
index f5daabc6..7bd55394 100644
--- a/src/serialport/qserialport_win.cpp
+++ b/src/serialport/qserialport_win.cpp
@@ -326,7 +326,7 @@ QSerialPort::PinoutSignals QSerialPortPrivate::pinoutSignals()
 
     if (!::GetCommModemStatus(descriptor, &modemStat)) {
         q->setError(decodeSystemError());
-        return QSerialPort::UnknownSignal;
+        return QSerialPort::NoSignal;
     }
 
     QSerialPort::PinoutSignals ret = QSerialPort::NoSignal;
@@ -890,7 +890,8 @@ void QSerialPortPrivate::detectDefaultSettings()
         dataBits = QSerialPort::Data8;
         break;
     default:
-        dataBits = QSerialPort::UnknownDataBits;
+        qWarning("%s: Unexpected data bits settings", Q_FUNC_INFO);
+        dataBits = QSerialPort::Data8;
         break;
     }
 
@@ -922,7 +923,8 @@ void QSerialPortPrivate::detectDefaultSettings()
         stopBits = QSerialPort::TwoStop;
         break;
     default:
-        stopBits = QSerialPort::UnknownStopBits;
+        qWarning("%s: Unexpected stop bits settings", Q_FUNC_INFO);
+        stopBits = QSerialPort::OneStop;
         break;
     }
 
@@ -936,8 +938,10 @@ void QSerialPortPrivate::detectDefaultSettings()
     } else if (currentDcb.fOutxCtsFlow && (currentDcb.fRtsControl == RTS_CONTROL_HANDSHAKE)
                && !currentDcb.fInX && !currentDcb.fOutX) {
         flow = QSerialPort::HardwareControl;
-    } else
-        flow = QSerialPort::UnknownFlowControl;
+    } else {
+        qWarning("%s: Unexpected flow control settings", Q_FUNC_INFO);
+        flow = QSerialPort::NoFlowControl;
+    }
 }
 
 QSerialPort::SerialPortError QSerialPortPrivate::decodeSystemError() const