PART A: Hardware settings
- 1 Have a look at your hardware specs!!! If not available look at the support page of your vendor, or contact the support hotline. You might also find the information in one of the hardware overviews mentioned above.
- 2 Use a current BIOS. Usually available at the support page of your vendor.
- 3 Try setserial /dev/ttyS? -g -a | egrep 16550A. One of the shown devices is probably the one you are looking for. Usually it is the second one, but with no guarantee.
- 4 Note: What seems like an UART is physically the IrDA controller. For my HP Omnibook 800 this is the VLSI VL82C147 PCI - IrDA controller. These controllers should behave up to 115 200 bps like UART's. But sometimes it is very difficult to get the right configuration.
PART B: How to tell the kernel about the hardware settings
-4 cat /dev/ioports to see which ports are already in use.
-5 cat /dev/interrupts to see which interrupts are already in use.
-6 Make ports and interrupts available for use with the IR device, e.g. stop the pcmcia service or include a line like this in /etc/sysconfig/pcmcia: PCIC_OPTS="irq_list=3,4,5,7,9,10,12,14,15"
-7 Now try to guess what the right interrupt and port is. Use setserial /dev/ttySx irq M port 0xNNNN to tell the kernel. If there is more then one possible chance try them all (Note: As mentioned in the Serial-HOWTO you should not try irq 0, 1, 6, 8, 13, 14).
-8 If you were successful please send the useful parameters to the author, because I would like to include them in the hardware overview.
-9 Good luck.
It might also be necessary to fine tune the IR serial port with setserial, e.g., setserial /dev/ttyS0 spd_vhi (speed rate 115200).
irattach hangs, but recognizes the printer. /var/log/messages shows that irattach found my HP LaserJet 6P.irattach &. Stop it if necessary with killall irattach. Recommendation by Andreas Butz: To my knowledge, <CTRL Z> bg should work, too, but I haven't tried it in this specific case. Normally it has the exact same effect as appending & to a command.
Note: Support for IrDA on 2.0.x kernels has been discontinued. You are encouraged to switch to 2.2.x kernels and use the newest IrDA patches available at http://www.cs.uit.no/~dagb/irda/snapshots/.
modprobe -a checks /lib/modules/<KERNEL-VERSION>/net/irda.o and causes the messages: "IrLAP; Missing IrTTY /IrLMP Error no IrLAP connection" (in /var/log/messages and on the console).
#!/bin/sh
echo "$0 : remove irda module"
rmmod irport.o
rmmod irtty.o
rmmod irda.o
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