Very Computer

hello-
        i just posted a similar question last week but couldn't get an answer.
I am using kernel 2.2.1 and most stuff works fine.  
        almost everything is a module including ppp and serial.  I can get ppp
and serial ports to work but only after setting the irq manually using
setserial EVERY TIME the module unloads.  
        what is the argument for /etc/conf.modules which will set the irq of
/dev/ttyS2 to 5?
where can I get more information like this in the future.  I can't find
anything on it in the linux/Documentation dir.
I use setserial /dev/ttyS2 irq 5 everytime I want to connect and it is
getting tiresome.
        if I set this in conf.modules will it remain?  
        I used to put this in my rc.serial script.  should I take this out?
                        thank you-              
                        eric