Subject: Re: port-alpha/21472 and kern/16379 (ohci/USB problems on Alpha)
To: NetBSD/alpha Discussion List <>
From: Nathan J. Williams <>
List: port-alpha
Date: 09/23/2004 17:50:00
"Greg A. Woods" <> writes:

> I find the following in sys/arch/alpha/pci/pci_6600.c:
> revision 1.2
> date: 2000/03/19 02:25:29;  author: thorpej;  state: Exp;  lines: +69 -26
> branches:  1.2.2;
> Add support for mapping the OHCI USB controller interrupt (which is wired toan ISA IRQ because it's in the same package as the PCI-ISA bridge).
> However on the ES40 the device probes as follows:
> 	ohci0 at pci0 dev 19 function 0: Acer Labs M5237 USB Host Controller (rev. 0x03)
> 	ohci0: interrupting at isa irq 10
> 	ohci0: OHCI version 1.0, legacy support
> So is it really on an ISA IRQ when it probes as a PCI device?

Probably, yes. There's no such thing as a "PCI interrupt controller"
at this level; the system can wire up the interrupt pins from the PCI
bus to whatever interrupt controller it likes, and on systems with ISA
bridges (usually just "legacy" keyboard/mouse/serial/parallel/floppy),
it's common to wire them up to the ISA interrupt controller that's
included as part of that package.

> According to the SRM's "show config" the only thing that actually seems
> to be on the ISA bus is the floppy (of the things it knows about):

It's not really "on the ISA bus", just using its interrupt
controller. Not that SRM can safely be considered authoritative for
ISA devices anyway.

> Does this suggest that Nathan's  patches for USB on PWS500au to
> pci_550.c still also need to be made to pci_6600.c?

Er, which patch was that?

> Shall I build a PCI_CONFIG_DUMP kernel?

You can get everything you need from userland with "pcictl /dev/pci0
dump -d 1 -f 2", with appropriate values for 0, 1, and 2.
        - Nathan