PCI interrupts

From: Matthew Clark (matt@eee.nott.ac.uk)
Date: Mon Nov 05 2001 - 18:43:35 EST


Dear kernel list,

I am writing a dev driver for a pci device and I am having some
difficultly getting the interrupts line.

As far as I understood the BIOS / kernel would sort out a unique
interrupt line for me which I could then get by registering with
the system.

In my development system the PCI card I am developing the
driver for reports (from the PCI config region) that it is using
interrupt 5. I can't register this interrupt as it is already
in use by the USB controller.

(a) should my card have a unique number- if so what should I
do?

(b) if it shouldn't have a unique number do I have to share the
interrupt (with the usb controller) or can I change it to
another address (by writing to the config space?)?
If I have to share it how do I do this- (my card will generate a
lot of interrupt traffic)?.

I have free interrupts and would prefer not to share the
interrrupt for this device.

Any help / suggestions gratefully received-

apologies if this is in the wrong place--

Thanks matt

snippet from lspci -v
.....
00:1f.2 USB Controller: Intel Corporation 82801AA USB (rev 02)
(prog-if 00 [UHCI])
        Subsystem: Intel Corporation 82801AA USB
        Flags: bus master, medium devsel, latency 0, IRQ 5
......
01:05.0 DMA controller: PLX Technology, Inc. PCI <-> IOBus
Bridge (rev 02) (prog-if 00 [8237])
        Subsystem: PLX Technology, Inc. PCI <-> IOBus Bridge
        Flags: medium devsel, IRQ 5
......
Ignore the PLX PCI id- the card developers didn't get their own
number.....

cat /proc/interrupts

           CPU0
  0: 2099604 XT-PIC timer
  1: 3541 XT-PIC keyboard
  2: 0 XT-PIC cascade
  3: 11 XT-PIC serial
  4: 1537 XT-PIC serial
  5: 0 XT-PIC usb-uhci
  8: 1 XT-PIC rtc
 11: 196886 XT-PIC eth0, i810@PCI:0:1:0
 14: 13005 XT-PIC ide0
 15: 0 XT-PIC ide1
NMI: 0
ERR: 0

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Nov 07 2001 - 21:00:28 EST