FC3 Irq Conflicts on Laptop

[James McKenzie]

John wrote:
> I first noticed this problem when I first got a PCMCIA atheros based
> wireless card to work. The problem begins whenever I start the wireless
> card and then plug in an external USB 2.0 hard drive, mount it, and then
> begin browsing the the drive using nautilus, xmms, etc... A quick look
> at 'top' shows the logging facilities in FC3, klogd and syslogd, taking
> up almost all of the cpu. I then look at the /var/log/messages log in
> which i find that the error
> 
> serial8250: irq 11 has too much work
> 
> is being added to the file at an incredible rate. This of course spurs
> me to check the IRQs in proc...
> 
> 
> cat /proc/interrupts
> CPU0
> 0: 1640085 XT-PIC timer
> 1: 1403 XT-PIC i8042
> 2: 0 XT-PIC cascade
> 9: 2 XT-PIC acpi
> 11: 164675 XT-PIC ohci1394, ALI 5451, ehci_hcd, ohci_hcd, ohci_hcd,
> yenta, yenta, yenta, yenta, ath0, eth0
> 12: 685 XT-PIC i8042
> 14: 33533 XT-PIC ide0
> 15: 36 XT-PIC ide1
> NMI: 0 ERR: 6
> 
> 
> I find it completely ridiculous that irq11 is so overloaded while other
> irqs are either empty or almost completely empty. I then look within the
> pcmcia.opts configuration file to see whether I can switch yenta to a
> different interrupt, I instruct the config parser to 'ignore' irq11.
> Changing this and then either restarting pcmcia or simply restarting the
> computer has absolutely no effect upon IRQs.
> 
> So I guess my question essentially spurs from something that I once read
> that seemed to suggest to me that pcmcia.opts is not the first file to
> be parsed, it is overridden by settings somewhere else. Which
> essentially boils down to this; where can I definitively set the irq
> used by pcmcia?

You might have to enable the second PCI IRQ in your systems BIOS before 
trying to divert it through software.  I'm wondering why you are getting 
the error, as IRQ 11 should be your PCI bus interrupt and you should not 
have an 8250 UART in your system.  I have as much as you do in my 
system, and I do not get this error.  However, PCI IRQ movement is more 
art than science.

-- 
James McKenzie