Restart of async reading when a QSP::clear() is called

The method QSP::clear() can stall reading in case of following
situations:

- at the moment when PurgeComm abort of previously started
asynchronous reading operation

- when a serial port is in hardware flow control mode

- when a serial port has a limited read buffer size

Therefore is necessary restart of asynchronous reading to enable
of the read sequence.

Change-Id: I7a722a1ee20ecba0dd631da96ca81d2937d7ca6b
Reviewed-by: Robert Kurjata <rkurjata@gmail.com>
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/serialport/qserialport_win.cpp b/src/serialport/qserialport_win.cpp
index 3174db5..84d1db7 100644
--- a/src/serialport/qserialport_win.cpp
+++ b/src/serialport/qserialport_win.cpp
@@ -282,6 +282,12 @@ bool QSerialPortPrivate::clear(QSerialPort::Directions directions)
         return false;
     }
 
+    // We need start async read because a reading can be stalled. Since the
+    // PurgeComm can abort of current reading sequence, or a port is in hardware
+    // flow control mode, or a port has a limited read buffer size.
+    if (directions & QSerialPort::Input)
+        startAsyncRead();
+
     return true;
 }