?What?, Port? Perhaps you're not aware that the O2 was made in like 1996, the Tezro was made in 2003. They have different architectures, just because they are MIPS doesn't mean all Irix drivers run on all Irix platforms (they absolutely don't). The Irix drivers for each machine series are DESIGNED to run ONLY on the support bare metal of those machine, SGI almost NEVER backported hardware support. Irix is extremely close to it's metal (that's why emulation is so hard).
If you literally tried copying them from a Tezro to an O2...it just say wrong IP ARCH version and that's it, it's not like people haven't tried that.
if you have the source code? Well please let me have a copy and I'd love that
It's true that the concept of a USB subsystem (as primitive as Irix knew it) does exist in newer Irix kernel versions, NO USB PCI Card drivers were backported to O2 from SGI. So while a newer kernels know somewhat of USB, there are no supported USB adapters for O2 to make use of it.
Also O2 is 32bit, Tezro and Fuel are 64bit...another reason compiled drivers won't run.