How disable the use of a IRQ from specific harware?

[Mario Bertrand <mbert@tbrq.org>]

Hi,

I want to disable IRQ 4 wich is taken for USB for a second serial
port. Since I don't use USB, it is possible to reserve or attribute
that IRQ for my modem (I have a serial modem port for ppp (IRQ 3) and
another for my palm pilot sync)? Because it seem that the kernel is
reserving IRQ 4 for USB even if I don't use it.

I have read pci, serial, lspci, setpci, lilo prompt, howto's and
man's... and I still can't find my way.

Thank's

--------------
Mario Bertrand
mbert@tbrq.org