Help with this code in Freebsd (fail)

[josejachuf]

Hi everyone

pyserial 3.5
python3.8
Freebsd 13.0

The following code works fine in Windows and Linux, but not in FreeBSD.

The code reads and writes on an Arduino device.

ser = serial.Serial('/dev/cuaU0')
while True:    
    ser.reset_input_buffer()
    ser_bytes = ser.readline()
    decoded_bytes = ser_bytes[0:len(ser_bytes) - 2].decode("utf-8")

    print('Bytes:', ser_bytes)
    print('UTF-8:', decoded_bytes)
   
    resp = ser.write(b'v')
    print('Resp:', resp)
    sleep(2)

In the loop, the first cycle is executed without error [1], but in the second cycle the line ser.reset_input_buffer() Give the following error:

File "/home/jose/desarrollos/fav/desarollo/venv/lib/python3.8/site-packages/serial/serialposix.py", line 683, in reset_input_buffer
self._reset_input_buffer()
File "/home/jose/desarrollos/fav/desarollo/venv/lib/python3.8/site-packages/serial/serialposix.py", line 677, in _reset_input_buffer
termios.tcflush(self.fd, termios.TCIFLUSH)
termios.error: (6, 'Device not configured')

What I see is that the error occurs here [2]

I controlled that the port has not been closed with ser.is_open and if the port is kept open

Some idea or help about this

Thanks a lot

[1] In Linux and Windows when running this resp = ser.write(b'v'), I can confirm this script through a sound, in FreeBSD this does not happen.
[2]

pyserial/serial/serialposix.py

Line 682 in baa7c78

def _reset_input_buffer(self):

[josejachuf]

I answer myself in case it is useful to someone .
After trying, Debuggear and searching, what I found is that you should see the following in

sysctl hw.usb.no_cs_fail=1

So I read this in Linux and Windows is default

This is related to the USB-Serial Adapter that I use CH340 USB<->RS232