[ltp] Error in ttyS0

[Juan Pablo Martinez Sanchez]

Hello everybody,

i'm newbie in this mailing-list, i have been reviewing the mails in
november and december and i'm really interested with the thread started by
S.Y.Medley about error in ttyS0, because i had and already have the same
problem.

I'm using a IBM ThinkPad 600X, distribution is LFS and kernel is 2.4.18.
When i boot in windows there is no problem on using the serial port, but
when i boot linux it was impossible to write in ttyS0, i tried:

>dmesg | grep tty

and

>cat /proc/ioports | grep serial

but there was not match.

So, the kernel was not seeing the serial port at booting (for sure the
kernel was compiled to support serial comms) time. And i tried to update
the bios from ITET45WW to ITET55WW (the steps are well described in the
IBM web) and so i achieved that the kernel recognizes the serial port, now
when trying:

>dmesg | grep tty

the result is:      ttyS00 at 0x03f8 (irq = 4) is a 16550A

and

>cat /proc/ioports | grep serial

the result is:      03f8-03ff : serial(auto)

And now when I try to write on ttyS0 (write(fd, buf, size) for example)
the result seems to be satisfactory because there is no error but it
really doesn't write. I am trying with MINITERM application to test the
serial comms between two PC's and until now the result is negative and i
don't know why. The null-modem cable and the MINITERM application are OK
because i have used them to communicate via serie two other PC's but when
i try to communicate the ThinkPad and other PC it does'nt run.

Do you know why can it be happenning?, now i am trying with MINICOM and
with setserial but i don't know at all what to do...

Thanks a lot in advance. Bye,

Juan Pablo Martinez.