Hi,

       From: Curt Sampson <cjs@cynic.net>
    Subject: Libretto L2 USB IRQ Mapping
      Date : Thu, 21 Feb 2002 14:55:56 +0900 (JST)
 Message-ID: <Pine.NEB.4.43.0202211448100.568-100000@angelic.cynic.net>

$ So I'm wondering where to go next with this? I don't really know
$ much about PIR setup, but I'm willing to try any ideas that anyone
$ has.

$ pcib0: Acer Labs M1543 PCI-ISA Bridge (rev. 0x00)
$ ohci0 at pci0 dev 20 function 0: Acer Labs M5237 USB Host Controller (rev. 0x03)

casio FIVA206 has same PCI-ISA Bridge and same ohci USB Host Controller.
T.SHIOZAKI" <tshiozak@astec.co.jp> made the patch for FIVA206.

<URL:ftp://ftp.netbsd.org/pub/NetBSD/misc/tshiozak/fiva20x/for-syssrc-2001-11-17/fiva-src-2001-11-25-1.diff.bz2>

The patch include below:
    1. config file(FIVA)
    2. PCIBIOS_INTR_FIXUP_TRIGGER hack
	sys/arch/i386/conf/files.i386			
	sys/arch/i386/pci/pci_intr_fixup.c			  
    3. apm hack
    4. pciide hack
    5. ohci hack
	sys/dev/pci/ohci_pci.c
	sys/dev/usb/ohci.c

I think that  2. and 5. may be clue for your problem.
How about checking the patch?

Regards!
---
 Masanori Kanaoka	kanaoka@ann.hi-ho.ne.jp