[nSLUG] Identifying I/O ports in use or associated with devs

Mike Spencer mspencer at tallships.ca
Mon Mar 17 04:08:33 ADT 2014

I there a way to determine which I/O port a module is using? Is there
a  way to determine what port is associated with a device that a
module *should* be using?

Nothing I've managed to figure out -- e.g. systool, modinfo inter alia
-- tells me this.

Why do I ask?

Late in the week I'll be going to try to help a friend, a Windows
"power user" who is a totally novice Linux user.  He has a Ubuntu
distro specifically compiled to support 3-axis machine controller
software and hardware.

He complains (rather ambiguously, obviously) that he has a failure,
something to to do with the parallel port and the "wrong address". As
a slightly educated but otherwise wild guess, I'm surmising that the
parport_pc module is starting with some default params and one, the I/O
port "address", is wrong.

I expect to be able to find the place (does Ubunto have
/etc/rc.d/rc.*?) to load the module explicitly. Module parport_pc has
optional params:

      /sbin/modprobe parport_pc [ io=0xiii [irq=j [dma=k]]]

but I have no idea how to determine which port is in use and which
might a better/correct one. A sample is given in /etc/rc.d/rc.modules
(on my Slackware 12.1 box) but I'm unclear on whether it's a
cookbookable incantation or a generic example.

Of course, it may turn out to be something much simpler.  I'm just
trying to do my homework beforehand.

- Mike

Michael Spencer                  Nova Scotia, Canada       .~. 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^

More information about the nSLUG mailing list