I have a USB IrDA that I got working with my IrDA printer (SiPiX compact printer A6) on the Windows side, using default 4000000 speed and 1.0ms turn-around time (in the driver config). The USB IrDA dongle is using SigmaTel chip. IR printing works using IrDA port and SiPiX driver.
I'm trying to get it working on my Linux side (same machine), especially when SiPiX driver already exists in the CUPS. I seem to be able to use standard USB FIR driver to see my IrDA and my printer, via
irattach irda0 -s, and then
irdadump. I'm unable to get anything from SIR with this USB dongle at all (e.g.
irattach /dev/ttyS1 -s).
If FIR is good enough, I'm guessing I'll need to create a serial port of some kind from the working FIR and then addressing it from CUPS, but I got stuck here.