Hi Folks,
	I recently got ahold of a Dell GXPro: it has both
a built-in ethernet device (see ex0 below), and a built-in
USB device (see uhci0 below.)  As you can see below they
are both assigned to irq 11, however the machine seems
to operate correctly.  I use the ex0 device, and I have
a printer attached to one of the USB ports: neither emit
any errors that I've noticed.  I include the relevant
dmesg output below.

I'm not very familiar with PCI configurations, but this
machine appears to have two PCI busses: the USB device
is on one bus and the ethernet device is on the other.

Regarding the fact that the USB and the ethernet devices
are both assigned irq 11 is this:

	a) an error. 

	b) a feature of having two PCI busses, as interrupts are
unique per bus.

	c) something else altogether?

Especially if b) above, can someone point me to online
documentation on the relationship between bus structure,
interrupts, and CPU?

	Thanks for any enlightenment.

	- Scott


===

NetBSD 1.4.2 (RHINE) #5: Sat Jul 22 20:07:33 PDT 2000
    root@srp4:/usr/src/sys/arch/i386/compile/RHINE
cpu0: family 6 model 1 step 9
cpu0: Intel Pentium Pro (686-class)
real mem  = 66715648
avail mem = 60022784
using 840 buffers containing 3440640 bytes of memory
mainbus0 (root)
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o enabled, memory enabled
pchb0 at pci0 dev 0 function 0
pchb0: Intel 82441FX PCI and Memory Controller (PMC) (rev. 0x02)
pcib0 at pci0 dev 13 function 0
pcib0: Intel 82371SB PCI-to-ISA Bridge (PIIX3) (rev. 0x01)
pciide0 at pci0 dev 13 function 1: Intel 82371SB IDE Interface (PIIX3)
pciide0: bus-master DMA support present
pciide0: primary channel wired to compatibility mode
wd0 at pciide0 channel 0 drive 0: <Maxtor 84320A8>
wd0: drive supports 16-sector pio transfers, lba addressing
wd0: 4134MB, 8960 cyl, 15 head, 63 sec, 512 bytes/sect x 8467200 sectors
wd0: 32-bits data port
wd0: drive supports PIO mode 4, DMA mode 2
pciide0: primary channel interrupting at irq 14
pciide0: secondary channel wired to compatibility mode
wd1 at pciide0 channel 1 drive 0: <Maxtor 86480D6>
wd1: drive supports 16-sector pio transfers, lba addressing
wd1: 6181MB, 13395 cyl, 15 head, 63 sec, 512 bytes/sect x 12658776 sectors
wd1: 32-bits data port
wd1: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2
pciide0: secondary channel interrupting at irq 15
wd0(pciide0:0:0): using PIO mode 4, DMA mode 2 (using DMA data transfers)
wd1(pciide0:1:0): using PIO mode 4, DMA mode 2 (using DMA data transfers)
uhci0 at pci0 dev 13 function 2: Intel 82371SB USB Host Controller (PIIX3) (rev. 0x01)
uhci0: interrupting at irq 11
uhci0: USB version 1.0
usb0 at uhci0
uhub0 at usb0
uhub0: Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 2 ports with 2 removable, self powered
ulpt0 at uhub0 port 1 configuration 1 interface 0
ulpt0: EPSON USB Printer, rev 1.00/1.00, addr 2, iclass 7/1
ppb0 at pci0 dev 14 function 0: Digital Equipment DECchip 21052 PCI-PCI Bridge (rev. 0x02)
pci1 at ppb0 bus 1
pci1: i/o enabled, memory enabled
ex0 at pci1 dev 8 function 0: 3Com 3c905-TX 10/100 Ethernet
ex0: interrupting at irq 11
ex0: MAC address 00:c0:4f:bf:f4:9c
nsphy0 at ex0 phy 24: DP83840 10/100 media interface, rev. 1
nsphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
vga0 at pci0 dev 16 function 0: Matrox MGA Millennium 2064W ("Storm") (rev. 0x01)
wsdisplay0 at vga0: console (80x25, vt100 emulation)
isa0 at pcib0
aic0 at isa0 port 0x340-0x35f irq 10
scsibus0 at aic0: 8 targets, 8 luns per target
st0 at scsibus0 targ 5 lun 0: <HP, T4000s, 1.10> SCSI2 1/sequential removable
st0: rogue, density code 0x45, 512-byte blocks, write-enabled
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
lpt0 at isa0 port 0x378-0x37b irq 7
sb0 at isa0 port 0x220-0x237 irq 5 drq 1 drq2 5: dsp v4.13
audio0 at sb0: full duplex