Update to a higher baudrate(460800 or 921600) is impossible on MacOS

[baweiji]

SerialPort Version

11.x.x

Node Version

v14.18.0

Electron Version

No response

Platform

Darwin xxx 21.6.0 Darwin Kernel Version 21.6.0: Thu Mar 9 20:08:59 PST 2023; root:xnu-8020.240.18.700.8~1/RELEASE_X86_64 x86_64

Architecture

No response

Hardware or chipset of serialport

No response

What steps will reproduce the bug?

const serialPort = new SerialPort({path:'xxx', baudRate:230400});

serialPort.update({baudRate:460800}, (err)=>{console.log(err)});

What happens?

Received error in callback, the detailed information is:

Error: Error: Invalid argument calling ioctl(.., IOSSIOSPEED, -1 )

What should have happened?

I have read the source code, I think it is due to the ToBaudConstant method in bindings-cpp/src/serialport_unix.cpp. It will convert the baudrate passed by user. For baudrate higher than 230400, it will convert to -1 on MacOS.

I have also tested on windows, no such issue.

Additional information

No response