reassigning IRQs for specific PCI slots...

From: Robert Bird
Date: Thu Nov 06 2003 - 10:27:49 EST



Hi,

We are trying to use RTLinux thread to service a PCI-based multi-port serial card. I have read several documents regarding "sharing IRQs", using boot-prompt parameters, IO-APIC.txt, etc. I am being told by the RTLinux community that I must not share interrupts when using real-time thread to service a PCI-based function. I have tried using several combinations of boot-prompt parameters (we are using GRUB) but have had no success in redirecting IRQ assignment during boot-time!

I have tried to use "pirq=" boot parameter.....the booting kernel does acknowledge the parameter but appears to forget about it when PCI probing occurs. It assigns my two PCI-based boards the same way each time: slot #1=5, slot #2=11. I have made some semi-smart attempts to use the "pci=" parameters "nobios", "noapic" (my kernel does not recognize this one), and "nosort" in conjunction with the "pirq=" parameter. [I guess my "semi-smart attempts" are not that smart].

Is it possible to do what I want to do? Would you have any ideas on what I could try next.

I am not using a multi-processor board but have selected the IO-APIC option before making the compiler.


What I am using:
- kernel: GPL 2.4.18 (with IO-APIC compiled in)
- RTLinux: 3.2-pre1
-Tyan motherboard with PIII
- gcc 3.2.1

Thanks in advance for taking the time to respond to my queries.

Regards.....Robert


++++++++++++++++++++++++++++++++++++++
Robert Bird
Senior Engineer, Electrical
Atlantic Positioning Systems
Atlantic Division, Atlantic Microwave Corporation
Internet Address: rbird@xxxxxxxxxxxxxxxxxxxxxxx
Internet Site: http://www.atlanticpositioners.com


6/11/2003
rbird@xxxxxxxxxxxxxxxxxxxxxxx
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