Re: /proc/interrupts - conflicts?
Brian Mays wrote:
> firstname.lastname@example.org (Mark Phillips) writes:
> > Can you tell, just by looking at /proc/interrupts, whether there is an
> > interrupt conflict?
> > In particular, how does it work for pcmcia cards for a laptop?
> Well, let's take a look. Here's what my /proc/interrupts says:
> 0: 3736694 timer
> 1: 60282 keyboard
> 2: 0 cascade
> 3: 22149 + serial
> 5: 1 sound blaster
> 9: 182163 3c589_cs
> 11: 8 i82365
> 13: 1 math error
> 14: 351147 + ide0
> Here's what this means:
> Interrupt 0: the timer
> Interrupt 1: the keyboard
> Interrupt 2: same as 9
> Interrupt 3: my serial mouse
> Interrupt 5: my sound card
> Interrupt 9: my PCMCIA network card
> Interrupt 11: the PCMCIA controller
> Interrupt 14: my hard drive
> You can search for conflicts caused by the PCMCIA utilities by listing
> the contents of /proc/interrupts with the PCMCIA card manager disabled
> (execute as root `/etc/init.d/pcmcia stop') and observing at what
> interrupts are being used. On my system, the sound card likes to use
> irq 5. Therefore, I exclude this interrupt from being used by a PCMCIA
> card by placing the following line in /etc/pcmcia/config.opts:
> exclude irq 5
> Without this line, my sound card does not work sometimes because the
> PCMCIA system seizes irq 5. This is evident in /proc/interrupts as a
> line such as
> 5: 2149 3c589_cs
> This shows that irq 5 has been assigned to my PCMCIA network card and
> hence is not available for use by the sound card.
> When worrying about interrupt conflicts, keep in mind that use irq 4
> is often used for the first and third serial ports and irq 3 is often
> used for the second and fourth serial ports. The parallel port likes
> to use irq 7, so you might want to exclude it in config.opts if you
> are hooked up to a printer or are using plip to connect to another
> computer. If, however, you never use your parallel port and your
> PCMCIA cards at the same time, then you probably don't need to worry
> about it.
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Also I have found that not all of the irq's are listed in
I had a problem some time ago and I found buried in /proc/pci is a
listing of devices used on the system: Here is what mine looks like:
PCI devices found:
Bus 0, device 10, function 0:
Ethernet controller: Realtek 8029 (rev 0).
Medium devsel. IRQ 5.
I/O at 0xfce0.
Bus 0, device 8, function 0:
VGA compatible controller: Cirrus Logic GD 5430 (rev 72).
Fast devsel. IRQ 11.
Prefetchable 32 bit memory at 0xfd000000.
Bus 0, device 1, function 0:
ISA bridge: VLSI 82C593-FC1 (rev 1).
Medium devsel. Fast back-to-back capable. Master Capable. No
Bus 0, device 0, function 0:
Host bridge: VLSI 82C592-FC1 (rev 1).
Medium devsel. Fast back-to-back capable. Master Capable.
and here is what /proc/interrupts shows:
0: 1519215 timer
1: 1367 keyboard
2: 0 cascade
3: 871156 + serial
5: 0 NE2000
8: 1 + rtc
9: 29117 + aha152x
10: 2 sound blaster
12: 601902 PS/2 Mouse
13: 1 math error
14: 26586 + ide0
notice that irq 11 is not listed in /proc/interrupts. This little
some serious problems with my sound card, and scsi controller when I
added the scsi
to my system. I hope that this helps.
_______ooO ~ Ooo_______________________________________________
LeRoy D. Cressy /\_/\ email@example.com
Computer Consulting ( o.o ) (215) 389-5870
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