Red Hat Bugzilla – Bug 23953
setserial changes irq setting for irq 9
Last modified: 2007-04-18 12:30:40 EDT
I have a PCI modem (US Robotics model 3CP5610A). The bus walk places
the modem at port 0xd400 and irq 9 (from /proc/pci). I use setserial
to set the port and irq values, but setserial changes my irq 9 request
to irq 2. The man page for setserial has the statement, "On AT class
machines, IRQ2 is seen as IRQ9 and Linux will interpret it in this
way." This may be fine for AT class machines, but this is disaster for
PCI - irq 2 is assigned to the process controller for cascade
This technique for configuring PCI modems is documented at
http://www.o2.net/~gromitkc/3cp5610.txt with a pointer to this page
from Red Hat.
What exactly are the bad effects that you see?
Apprently this works fine in 7.1. Closing.