2001-03-03 00:54:43

by Gregoire Favre

[permalink] [raw]
Subject: IRQ advice (2.4.2-ac7)

Hello,

as I boot some times under windows, i have to change my IRQ for my PCI
devices to (all) 9... and all the times I tried to boot that way under linux,
it doesn't boot...

So I haven't tested it that way for ages... and now with 2.4.2-ac7 i booted
without any problem that way:
cat /proc/interrupts 03.03 1:52
CPU0
0: 3051534 XT-PIC timer
1: 37390 XT-PIC keyboard
2: 0 XT-PIC cascade
8: 1 XT-PIC rtc
9: 6193814 XT-PIC HiSax, aic7xxx, EMU10K1, usb-uhci, saa7146(1), bttv
12: 314048 XT-PIC PS/2 Mouse
14: 11820 XT-PIC ide0
15: 42041 XT-PIC ide1
NMI: 27599
LOC: 3051630
ERR: 0
MIS: 0

Is it safe to do it that way?

Thanks you very much,

Greg
________________________________________________________________
http://ulima.unil.ch/greg ICQ:16624071 mailto:[email protected]


2001-03-03 01:36:55

by Jeremy Jackson

[permalink] [raw]
Subject: Re: IRQ advice (2.4.2-ac7)

Favre Gregoire wrote:

> Hello,
>
> as I boot some times under windows, i have to change my IRQ for my PCI
> devices to (all) 9... and all the times I tried to boot that way under linux,
> it doesn't boot...
>
> So I haven't tested it that way for ages... and now with 2.4.2-ac7 i booted
> without any problem that way:
> cat /proc/interrupts 03.03 1:52
> CPU0
> 0: 3051534 XT-PIC timer
> 1: 37390 XT-PIC keyboard
> 2: 0 XT-PIC cascade
> 8: 1 XT-PIC rtc
> 9: 6193814 XT-PIC HiSax, aic7xxx, EMU10K1, usb-uhci, saa7146(1), bttv
> 12: 314048 XT-PIC PS/2 Mouse
> 14: 11820 XT-PIC ide0
> 15: 42041 XT-PIC ide1
> NMI: 27599
> LOC: 3051630
> ERR: 0
> MIS: 0
>
> Is it safe to do it that way?

I personally don't like sharing interrupts unles absolutely necessary.
Can you tell me why you need to do this? I would recommend
disabling any devices you aren't using in the BIOS,
to free up interrupts. (IE 2nd serial port, USB, 1st serial if you
only use PS/2 mouse)

If you don't use the floppy you might be able to disable it in BIOS.
I have one board that will use irq 6 for something more useful in this
case.

Also, changing PCI slot assignment of some cards (if you have spare
slots) can prevent sharing as well.

The BIOS on many boards will show PCI interrupt assignment
on the bootup screen. Otherwise check in windows
device manager - double click on Computer node.

according to the above usage, you could use 4 (com1) (if not mouse or modem)
3 com2
5 unused
9,10,11

for devices.

Good luck!