linux - How set serial port

Question

In my linux distribution "buildroot" I'd like to set up the serial port as below but I get errors:

# stty -F /dev/ttyS4 -a
stty: can't open '/dev/ttyS0': No such file or directory
# stty -F /dev/ttyS0 9600 cs8 -cstopb -parenb
stty: /dev/ttyS0: Input/output error

When I check the serial port file permissions, everything looks fine:

# ls -al /dev/ttyS*
crw-------    1 root     root        4,  64 Jan  1 01:00 /dev/ttyS0
crw-------    1 root     root        4,  65 Jan  1 01:00 /dev/ttyS1
crw-------    1 root     root        4,  66 Jan  1 01:00 /dev/ttyS2
crw-------    1 root     root        4,  67 Jan  1 01:00 /dev/ttyS3

What could I do?

question from:https://stackoverflow.com/questions/66060508/how-set-serial-port

Answer 1

Waitting for answers