id summary reporter owner description type status milestone component version severity resolution keywords cc 12295 Boost Asio Serial Port does not work with Exar (Baudrate zero) Andreas Schmitz chris_kohlhoff "Calling boost::asio::serial_port.open(""COM4"") returns a error under windows. We use a Exar XR22804 using the latest official drivers for Windows. The problem is located in boost::asio::win_iocp_serial_port_service where the windows driver returns dcb.Baudrate=0. After that it tries to set new settings with SetCommState and it fails if dcb.Baudrate is 0. A solution would be to preset the baudrate if 0 or even better to read a user parameter with the wanted baudrate as it is done in some other frameworks. Someone else has sent the same bug to the people of the qt-framework, and they solved it: https://bugreports.qt.io/browse/QTBUG-46993" Bugs new To Be Determined asio Boost 1.61.0 Problem serial port exar windows baudrate zero