port-i386/46808: 6.0_BETA2 install crashes on VIA VT6202 detection

[jc.lynx_AT_laposteDOTnet%NetBSD.org@localhost]

>Number:         46808
>Category:       port-i386
>Synopsis:       6.0_BETA2 install crashes on VIA VT6202 detection
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Aug 17 19:40:00 +0000 2012
>Originator:     Jean-Charles
>Release:        6.0_BETA2
>Organization:
>Environment:
>Description:
When booting from the 6.0_BETA2 i386 install CD (NetBSD-6.0_BETA2-i386.iso) on 
a Compaq Presario 2500 (EA2528), I encounter a crash on EHCI USB initialisation.

End of dmesg :

uhci0 at pci0 dev 11 function 0: vendor 0x1106 product 0x3038 (rev. 0x50)
uhci0: interrupting at irq 10
usb0 at uhci0: USB revision 1.0
uhci1 at pci0 dev 11 function 1: vendor 0x1106 product 0x3038 (rev. 0x50)
uhci1: interrupting at irq 10
usb1 at uhci1: USB revision 1.0
ehci0 at pci0 dev 11 function 2: vendor 0x1106 product 0x3104 (rev. 0x51)
ehci0: interrupting at irq 11
ehci0: dropped intr workaround enabled
panic: kernel diagnostic assertion "maxncomp <= EHCI_COMPANION_MAX" failed: 
file "/usr/src/sys/dev/pci/ehci_pci.c", line 230
fatal breakpoint trap in supervisor mode
trap type 1 code 0 eip c026eb64 cs 8 eflags 282 cr2 0 ilevel 8

Same problem with 6.0_BETA. The USB 2.0 controller is a VIA VT6202.

I then tried the 5.1.2 install CD. If I understand, EHCI didn't work either, 
but that didn't crash the boot process. The USB messages were these :

uhci0 at pci0 dev 11 function 0: vendor 0x1106 product 0x3038 (rev. 0x50)
uhci0: interrupting at irq 10
usb0 at uhci0: USB revision 1.0
uhci1 at pci0 dev 11 function 1: vendor 0x1106 product 0x3038 (rev. 0x50)
uhci1: interrupting at irq 10
usb1 at uhci1: USB revision 1.0
ehci0 at pci0 dev 11 function 2: vendor 0x1106 product 0x3104 (rev. 0x51)
ehci0: can't map memory space

>How-To-Repeat:

>Fix: