Two PnP cards wanting the same IRQ

[guitardude]

I've got a 3Com 56K PnP modem that is defaulting to IRQ 5; however the SB-compatible sound card is also wanting IRQ 5.

How can I force the modem to take a different IRQ? I think it's running on COM 3, so the IRQ should be either 3 or 4; not 5 as it is now. A point in the right direction would be greatly appreciated. :)

[WCox]

You may have to try putting one of the cards into another pci slot.


:cool: Slackware :cool:
:) Debian (as a back-up) :)

[WCox]

Or...... See if the one of the cards has jumpers that may let you change the IRQ of the card.

:cool: Slackware :cool:
:) Debian (yes as a back-up) :)

[bdg1983]

Also try turning off 'PnP OS' in the BIOS as it may help assign the IRQ's.

You may be able to force modem to use another IRQ. Check some of the NHF's here for any that have examples of doing this. You can start with the Modem sections of course.

Searching the forums will also most likely give you the answer.

[guitardude]

Ok guys; both cards are ISA peripherals, so I don't think switching a slot will do any good. I will however, look to see if I can find a jumper on one/both of the cards so I can reassign the IRQ of at least one of them.

The machine is a dual boot Win98/RH7 box; if I turn PnP off in the BIOS, wouldn't that screw with the operation of Windows? Or would it mean that I would have to manually configure IRQ's in the BIOS and/or Windows?

In the end, I guess I'll probably need to adjust the BIOS settings to get them to play nice.

Thx,
-guitardude

[ 28 March 2001: Message edited by: guitardude ]

[bdg1983]

Sorry as I didn't notice in your original post that you said they are both ISA.

Do either of the cards come with a Dos configuration utility on the driver diskette that you can run to manually change the IRQ and IO of either one of the cards?

I know that ISA nics include this utility or is available as a download.

[Soccerman]

I've often wondered since I got Linux..

why must I disable PnP OS (and what exactly does that do to the computer and windows)?? Linux surely can configure PCI cards fine, why not ISA PnP compatible cards?

and what happens when cards want the same IRQ? can't you just point them towards a different IRQ??

the reason I ask, is that I have had to disable my USB ports (in the BIOS) in order to keep them from using the IRQ my PCI hardware modem uses, I shouldn't have to do such a thing!

if Disabling PnP OS somehow didn't solve that problem (say there was still an IRQ conflict), how would I solve it? moving cards around is something I'd rather not do, since they are in an optimal position for cooling..

and finally, I have a problem of my own. where do I enter the information for my ISA non-PnP NIC to set the device to be eth0??

[ 21 April 2001: Message edited by: Soccerman ]

[bdg1983]

where do I enter the information for my ISA non-PnP NIC to set the device to be eth0??


If you only have 1 nic and it is detected of course, then it can only be eth0. Are you talking about IRQ's and I/O address for ISA nics?

Most ISA cards include a dos configuration utility on the driver diskette or downloadable that you use to turn off PnP or change the IRQ and I/O.

Just in case you need this...

To List the Resources Used by your System

cat /proc/pci
cat /proc/interrupts
cat /proc/ioports

ISA PnP

pnpdump > /etc/isapnp.conf

Hope I've answered or cleared up some of your questions. If not, please post back.

[Soccerman]

If you only have 1 nic and it is detected of course, then it can only be eth0. Are you talking about IRQ's and I/O address for ISA nics?

yeah, I just want to enter the I/O, and IRQ..

it has jumpers on it, and I think it might have been possible to set it up using software (cause there's a software setup position that could be selected by jumper).

BTW, my NIC is set (by the jumpers) to use IRQ 3, and I/O 0280-029F. The IRQ does NOT appear when I type cat interrupts (from the /proc directory), and neither does the I/O number.

And, as expected, cat pci command doesn't show anything, relavent to the NIC, becuase it is ISA.

[ 21 April 2001: Message edited by: Soccerman ]

[bdg1983]

The only ISA card I currently have in one of my home PC's, is a Roland soundcard. Haven't bothered setting it up in Linux as I use Win98/Cakewalk Pro Audio. Will try soon as I just purchased the Abit KT7A which has 1 ISA slot and this time I will work on getting it to work.

Anyways...

Did you try 'pnpdump > /etc/isapnp.conf'. It's just something I've picked up from previous posts here and there should be man pages for either/both pnpdump or isapnp.

Give that a try and let us know the results.

There is a NHF on ISA modems that may assist you in setting up a ISA nic. You never know.

[Soccerman]

ok, I did the pnpdump > /etc/isapnp.conf command, and all that appears to have done is searched all of the I/O ports.. none of which turned up anything.

what does this mean? I know at least 1 of those addresses should have returned something (it matched what is set by the jumper on the card).

[Lorithar]

*shakes head to clear out the sleepdust*


Good Morning boys and girls.

1) Turning off PNP aware OS in the bios won't kill your windows ability to use installed hardware. It *can* cause issues when installing brand spanking new devices to windows which are not properly registered with MS's PNP database, but with the standardization most companies use to set the PNP data its less likely these days.
This function simply allows the BIOS to look at all the cards in the system when it boots, collect all control data, fire it into a table, sort it out to figure what can share irqs with what, etc etc etc ... something most systems really shouldnt' require .. unless you're like some of my friends who have every slot occupied with odd bits.
Unfortunately when you do this the BIOS owns the controls and IRQs for all PNP cards in your system and the OS cannot issue thngs like reset to the card ... which makes linux unhappy.

do a
dmesg |more
and see what your boot sequence has to say about your devices ... there may be more info there that can help here.

IRQ 3 is normally a COM port irq ...

/proc should have devices and interrupts and ioports
These files will tell you what the system can see on your motherboard. It takes some looking but you can sometimes find that linux has moved the device somewhere it can work with it.

Most ISA based cards will have a dos utility that will let you set them up a certain way if they don't have pin based settings. You may be able to sort it out.
Check /proc/interrupts for available irqs and /proc/ioports for availble io settings.

[Soccerman]

about the IRQ thing, I have all of my Serial ports disabled.

Also, I have my USB devices disabled, becuase they interfere (with PnP OS enabled at least) with my 56K PCI modem.

[Soccerman]

ok, I tried that dmesg |more command, and it didn't really help.. near the bottom it says that it runs ISAPNP, and it says no devices found.

isn't it possible to simply point Linux to the card whose resourses I know (IRQ3, I/O 280-029F etc)?

I'm going to try one other thing: disabling PnP OS..

[Soccerman]

c'mon, I should just be able to point Linux to the correct device, even though it doesn't show up in these probes?

[bdg1983]

???

Did you try some of the suggestions in the ISA modem NHF? May help.

Other than that, I wouldn't know what to try next unless doing more research.

[bdg1983]

Have a look at this (http://www.linuxnewbie.org/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic&f=13&t=004210) thread. Near the bottom it mentions about the order you load in modules.conf and may help you.

[Soccerman]

ok, I'll take a look at that link. I've looked at the NHF's before, but didn't think they applied to me, so I'll check it again! thanks for the help!