Serial port (com1) baud rate oddity

[Richard P. Williamson]

At 17:41 22/03/2004, Nathan Kinkade wrote:
>On Mon, Mar 22, 2004 at 04:14:56PM +0000, Richard P. Williamson wrote:
>> Hello,
>> 
>> I'm using 4.8 Release on an embedded pentium class device,
>> and I'm having trouble with the serial (console) port.
>> 
>>  From a development machine, I can 'tip com1' and get contact,
>> but the data is coming out as 
>> @@@ @ @@@ @@@   @@@  @@@@@@@@@@@ @@@ @@@@@@  @@@@@ @  @ @@@
>> @ @@    @@@ @ @ @@@@@ @ @@@@ @@@@@@ @ @@@ @@ @ @@@@ @@@@@  @
>> @  @@    @   @ @ @@@@ @ @@@@  @@@@@ @@@ @@ @ @@@@ @@@  @@   
>> etc
><snip>
>> Also minor problem, is this the reason why I can't talk out com3:
>> "sio2: configured irq 5 not in bitmap of probed irqs 0"
><snip>
>
>tip gets it configurations from /etc/remote.  Make sure that "com1" in
>/etc/remote is set with appropriate values.  The default is:
>
>sio0|com1:dv=/dev/cuaa0:br#9600:pa=none:

That's what I have.  And it was working up to the beginning of
last week.  Strangely, my son was born on Friday the 12th, and
since then my console port no longer works.  I'm sure they aren't
directly related.  However I may have changed something while
distracted by my wife screaming she was going to kill me.

>The output above looks to me like the problem is simply with the bit
>rate.  Try some other values.  You can specify them manually on the tip
>command line with the -s option.

I have tried resetting the baud rate using stty, since I'm
trying to change the source machine back to 9600.  I'll see
if using tip -s 1355 works on the sink machine this morning.
One thing I tried returned 'TCSGETATTR: incorrect attribute'
or something when trying to set the sink to 1355, however. 

>Regarding your problem with sio2, possibly your kernel is configured
>specifying an extra serial port that doesn't actually exist on the
>hardware?  How many physical serial ports does your device actually
>have?

4.  com1 and com3 out through DB9s (male).  com2 is attached to a
densitron 2x16 LCD screen.  com4 is unused (but the connector on
the motherboard is there).

Thanks for your time!

rip