bad Irq for Intel 82371AB USB on Mitac 6120

[Hanspeter Roth <hanspeter_roth_(_at_)_hotmail_(_dot_)_com>]

I have installed Openbsd 3.0 on a Mitac 6120.
In the boot log I get:

uhci0 at pci0 dev 7 function 2 "Intel 82371AB USB" rev 0x01pci_intr_map: bad interrupt line 128

Runing top shows >20% interrupt.

Often the boot process hangs after wd0(pciide0:0:0).

With Linux 2.2.18 I also get Irq 128. But I have no problem to boot.
With Linux 2.4.2 and Win 98 the uhci gets irq 9.

With boot_config I could supply a device and a function but no irq.
Can one somehow preset the irq for the uhci*?

-Hanspeter