Sticky IO-APIC problem

From: Colin Bayer (
Date: Mon Jul 02 2001 - 04:25:23 EST

('binary' encoding is not supported, stored as-is) 'K, here's the deal.

I have a Pentium III 933/133 (Coppermine, stepping 6) in an Intel-manufactured i810 motherboard (hey, I know it's a lame chipset, but it was on sale). On boot, the kernel (version 2.4.6-pre8) identifies and maps the IO-APIC onboard, but does not assign any IRQs to it.

The relevant boot log snippet follows.

[root@fortytwo i386]# cat /var/log/dmesg
mapped APIC to ffffe000 (0121c000)
Kernel command line: auto BOOT_IMAGE=linux-test ro root=307 BOOT_FILE=/boot/vmlinuz-2.4.6-pre8 devfs=mount pirq=9,4
PIRQ redirection, working around broken MP-BIOS.
... PIRQ0 -> IRQ 9
... PIRQ1 -> IRQ 4

And /proc/interrupts:
[root@fortytwo i386]# cat /proc/interrupts
  0: 79409 XT-PIC timer
  1: 5911 XT-PIC keyboard
  2: 0 XT-PIC cascade
  4: 990 XT-PIC es1371
  8: 1 XT-PIC rtc
  9: 26402 XT-PIC usb-uhci, serial
 11: 16473 XT-PIC i810@PCI:0:1:0
 14: 5152 XT-PIC ide0
 15: 47 XT-PIC ide1
NMI: 0
ERR: 0
MIS: 0
[root@fortytwo i386]#

This problem also occurs when booting without the pirq switch. I've configured everything the way it's mentioned in Documentation/i386/IO-APIC.txt, but it doesn't help. Anyway, thx in advance for the help.

     -- Colin

The CompNerd Network:
Where a nerd can be a nerd. Get your free!
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Sat Jul 07 2001 - 21:00:10 EST