Re: Help enabling PCI interrupts on Dell/SMP and Sun/SMP systems.

From: linux-os
Date: Wed Feb 23 2005 - 15:50:04 EST


On Wed, 23 Feb 2005, Alan Kilian wrote:

call pci_enable_device(dev)
... before you use the IRQ in dev->irq.

The reported IRQ is bogus until you make that
call. It's a reported BUG, probably won't
ever get fixed because it's considered a
feature.

Also, make sure that your .config for the Dell looks
something like:

CONFIG_X86_IO_APIC=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_PCI=y
# CONFIG_PCI_GOBIOS is not set
# CONFIG_PCI_GODIRECT is not set
CONFIG_PCI_GOANY=y
CONFIG_PCI_BIOS=y
CONFIG_PCI_DIRECT=y



Folks,

This group was instrumental in helping me get my first-ever
linux/PCI-bus device driver working last year, and I'm back for
some more help if you are willing.

I have a PCI card that generates an interrupt when it completes
a DMA transfer to the PCs RAM.

This works just fine on a Dell 4400 running 2.6.10-1.766_FC3

When I try to run the driver on a Dell 2300 FC2/2.6.5-1.358smp
or a Sun W2100Z running FC2/2.6.10-1.14_FC2smp I can see the
DMA-done bit set in the device, but my interrupt service routine
never gets called.

On the Sun, I booted with "noapic" option, and it booted OK,
but then when my device generated an interrupt, there was a
kernel message about Disabling IRQ #5 and the system was hung
solidly.

I think this has something to do with the different interrupt
hardware on the more advanced servers compared to my desktop
Dell 4400, and I somehow need to "enable" the IOAPIC system
so that my interrupt gets through to my service routine, but I
don't know how.

I tried grepping through the kernel/drivers source, and I didn't
find anything that jumped out at me.

The Rubini drivers book didn't help in this area either,
although it's a wonderful book in other areas.

I can post source somewhere if it will help.

I can also post the essential bits from /var/log/messages about
all the incredibly complicated IOAPIC configuration stuff.

Thank you for your past help, and thank you in advance for any
tips you can provide.

-Alan

--
- Alan Kilian <kilian(at)bobodyne.com>


Cheers,
Dick Johnson
Penguin : Linux version 2.6.10 on an i686 machine (5537.79 BogoMips).
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