>
> Is there a reason for this? I don't think there are any AMD64 or EMT64
> systems which only support USB 1.1.
>
very good reason. ehci prevents some devices on some machines to work at 
all, while they works with USB 1.1 only (ohci)!

at least on my machine (below) that runs custom kernel with ehci disabled, 
or url(4) doesn't work.

Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
     The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993
     The Regents of the University of California.  All rights reserved.

NetBSD 3.99.7 (3miasto.net) #6: Tue Aug 30 21:17:32 CEST 2005
 	root@serwer.3miasto.net:/usr/src/sys/arch/amd64/compile/3miasto.net
total memory = 1023 MB
avail memory = 982 MB
mainbus0 (root)
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: AMD Athlon(tm) 64 Processor 2800+, 1808.89 MHz
cpu0: features: e7dbfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>
cpu0: features: e7dbfbff<PGE,MCA,CMOV,PAT,PSE36,MPC,NOX,MMXX,MMX>
cpu0: features: e7dbfbff<FXSR,SSE,SSE2,LONG,3DNOW2,3DNOW>
cpu0: I-cache 64 KB 64B/line 2-way, D-cache 64 KB 64B/line 2-way
cpu0: L2 cache 512 KB 64B/line 16-way
cpu0: ITLB 32 4 KB entries fully associative, 8 4 MB entries fully associative
cpu0: DTLB 32 4 KB entries fully associative, 8 4 MB entries fully associative
cpu0: calibrating local timer
cpu0: apic clock running at 200 MHz
cpu0: 8 page colors
ioapic0 at mainbus0 apid 2 (I/O APIC)
ioapic0: pa 0xfec00000, version 11, 24 pins
acpi0 at mainbus0
acpi0: using Intel ACPI CA subsystem version 20050408
acpi0: X/RSDT: OemId <Nvidia,AWRDACPI,42302e31>, AslId <AWRD,00000000>
acpi0: SCI interrupting at int 9
acpi0: fixed-feature power button present
acpi0: fixing up intr link \_SB_.PCI0.LMAC
acpi0: fixing up intr link \_SB_.PCI0.LMCI
acpi0: fixing up intr link \_SB_.PCI0.LIDE
acpi0: fixing up intr link \_SB_.PCI0.LSID
acpi0: fixing up intr link \_SB_.PCI0.LNK5
acpi0: fixing up intr link \_SB_.PCI0.L3CM
ACPI Object Type 'Processor' (0x0c) at acpi0 not configured
acpi: activated PNP0C0F
acpi: activated PNP0C0F
PNP0C02 [Plug and Play motherboard register resources] at acpi0 not configured
acpibut0 at acpi0 (PNP0C0C): ACPI Power Button
PNP0C01 [System Board] at acpi0 not configured
PNP0A03 [PCI Bus] at acpi0 not configured
ACPI Object Type 'Power' (0x0b) at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C0F [PCI interrupt link device] at acpi0 not configured
PNP0C02 [Plug and Play motherboard register resources] at acpi0 not configured
PNP0000 [AT Interrupt Controller] at acpi0 not configured
PNP0200 [AT DMA Controller] at acpi0 not configured
attimer0 at acpi0 (PNP0100): AT Timer
attimer0: io 0x40-0x43 irq 0
PNP0B00 [AT Real-Time Clock] at acpi0 not configured
pcppi0 at acpi0 (PNP0800)
pcppi0: io 0x61
sysbeep0 at pcppi0
PNP0C04 [Math Coprocessor] at acpi0 not configured
fdc0 at acpi0 (PNP0700)
fdc0: io 0x3f0-0x3f5,0x3f7 irq 6 drq 2
com0 at acpi0 (PNP0501-1)
com0: io 0x3f8-0x3ff irq 4
com0: ns16550a, working fifo
lpt0 at acpi0 (PNP0400)
lpt0: io 0x378-0x37f,0x778-0x77b irq 7
pcppi0: attached to attimer0
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
pchb0 at pci0 dev 0 function 0
pchb0: Nvidia nForce3 250 Host-PCI bridge (rev. 0xa1)
pcib0 at pci0 dev 1 function 0
pcib0: Nvidia nForce3 250 PCI-ISA bridge (rev. 0xa2)
Nvidia nForce3 250 SMBus Controller (SMBus serial bus, revision 0xa1) at pci0 dev 1 function 1 not configured
ohci0 at pci0 dev 2 function 0: Nvidia nForce3 250 USB Host Controller (rev. 0xa1)
ohci0: interrupting at ioapic0 pin 5 (irq 5)
ohci0: OHCI version 1.0, legacy support
usb0 at ohci0: USB revision 1.0
uhub0 at usb0
uhub0: Nvidia OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub0: 4 ports with 4 removable, self powered
ohci1 at pci0 dev 2 function 1: Nvidia nForce3 250 USB Host Controller (rev. 0xa1)
ohci1: interrupting at ioapic0 pin 5 (irq 5)
ohci1: OHCI version 1.0, legacy support
usb1 at ohci1: USB revision 1.0
uhub1 at usb1
uhub1: Nvidia OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 4 ports with 4 removable, self powered
Nvidia nForce3 250 USB2 Host Controller (USB serial bus, interface 0x20, revision 0xa2) at pci0 dev 2 function 2 not configured
auich0 at pci0 dev 6 function 0: nForce3 250 MCP-T AC-97 Audio
auich0: interrupting at ioapic0 pin 11 (irq 11)
auich0: ac97: Avance Logic ALC850 codec; no 3D stereo
auich0: ac97: ext id 9c6<AC97_23,LDAC,SDAC,CDAC,SPDIF,DRA>
viaide0 at pci0 dev 8 function 0
viaide0: NVIDIA nForce3 250 IDE Controller (rev. 0xa2)
viaide0: bus-master DMA support present
viaide0: primary channel configured to compatibility mode
viaide0: primary channel interrupting at ioapic0 pin 14 (irq 14)
atabus0 at viaide0 channel 0
viaide0: secondary channel configured to compatibility mode
viaide0: secondary channel interrupting at ioapic0 pin 15 (irq 15)
atabus1 at viaide0 channel 1
viaide1 at pci0 dev 10 function 0
viaide1: NVIDIA nForce3 250 Serial ATA Controller (rev. 0xa2)
viaide1: bus-master DMA support present
viaide1: primary channel wired to native-PCI mode
viaide1: using ioapic0 pin 11 (irq 11) for native-PCI interrupt
atabus2 at viaide1 channel 0
viaide1: secondary channel wired to native-PCI mode
atabus3 at viaide1 channel 1
ppb0 at pci0 dev 11 function 0: Nvidia nForce3 250 AGP (rev. 0xa2)
pci1 at ppb0 bus 1
pci1: i/o space, memory space enabled
ppb1 at pci0 dev 14 function 0: Nvidia nForce3 250 PCI-PCI bridge (rev. 0xa2)
pci2 at ppb1 bus 2
pci2: i/o space, memory space enabled
rtk0 at pci2 dev 6 function 0: Realtek 8139 10/100BaseTX
rtk0: interrupting at ioapic0 pin 3 (irq 3)
rtk0: Ethernet address 00:a1:b0:a1:df:de
ukphy0 at rtk0 phy 7: Generic IEEE 802.3u media interface
ukphy0: OUI 0x000000, model 0x0000, rev. 0
ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
vga0 at pci2 dev 7 function 0: Tseng Labs ET6000 (rev. 0x30)
wsdisplay0 at vga0 (kbdmux ignored): console (80x25, vt100 emulation)
puc0 at pci2 dev 8 function 0: Titan PCI-800H (com, com, com, com)
com2 at puc0 port 0: interrupting at ioapic0 pin 10 (irq 10)
com2: ns16550a, working fifo
com3 at puc0 port 1: interrupting at ioapic0 pin 10 (irq 10)
com3: ns16550a, working fifo
com4 at puc0 port 2: interrupting at ioapic0 pin 10 (irq 10)
com4: ns16550a, working fifo
com5 at puc0 port 3: interrupting at ioapic0 pin 10 (irq 10)
com5: ns16550a, working fifo
puc1 at pci2 dev 8 function 1: Titan PCI-800H (com, com, com, com)
com6 at puc1 port 0: interrupting at ioapic0 pin 10 (irq 10)
com6: ns16550a, working fifo
com7 at puc1 port 1: interrupting at ioapic0 pin 10 (irq 10)
com7: ns16550a, working fifo
com8 at puc1 port 2: interrupting at ioapic0 pin 10 (irq 10)
com8: ns16550a, working fifo
com9 at puc1 port 3: interrupting at ioapic0 pin 10 (irq 10)
com9: ns16550a, working fifo
fxp0 at pci2 dev 9 function 0: i82550 Ethernet, rev 16
fxp0: interrupting at ioapic0 pin 5 (irq 5)
fxp0: Ethernet address 00:07:e9:0a:04:1a
inphy0 at fxp0 phy 1: i82555 10/100 media interface, rev. 4
inphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
rtk1 at pci2 dev 10 function 0: Realtek 8139 10/100BaseTX
rtk1: interrupting at ioapic0 pin 10 (irq 10)
rtk1: Ethernet address 00:02:44:9c:15:b0
ukphy1 at rtk1 phy 7: Generic IEEE 802.3u media interface
ukphy1: OUI 0x000000, model 0x0000, rev. 0
ukphy1: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
pchb1 at pci0 dev 24 function 0
pchb1: Advanced Micro Devices AMD64 HyperTransport configuration (rev. 0x00)
pchb2 at pci0 dev 24 function 1
pchb2: Advanced Micro Devices AMD64 Address Map configuration (rev. 0x00)
pchb3 at pci0 dev 24 function 2
pchb3: Advanced Micro Devices AMD64 DRAM configuration (rev. 0x00)
pchb4 at pci0 dev 24 function 3
pchb4: Advanced Micro Devices AMD64 Miscellaneous configuration (rev. 0x00)
isa0 at pcib0
ioapic0: enabling
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
audio0 at auich0: full duplex, independent
url0 at uhub0 port 1
url0: USBKR100 USB 10/100 LAN, rev 1.10/1.00, addr 2
url0: Ethernet address 00:10:60:db:5b:c2
urlphy0 at url0 phy 0: Realtek RTL8150L internal media interface
urlphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
wd0 at atabus0 drive 0: <WDC WD2000JB-00FUA0>
wd0: drive supports 16-sector PIO transfers, LBA48 addressing
wd0: 186 GB, 387621 cyl, 16 head, 63 sec, 512 bytes/sect x 390721968 sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
wd0(viaide0:0:0): using PIO mode 4, Ultra-DMA mode 5 (Ultra/100) (using DMA)
boot device: wd0
root on wd0a dumps on wd0b
wsdisplay0: screen 1 added (80x25, vt100 emulation)
wsdisplay0: screen 2 added (80x25, vt100 emulation)
wsdisplay0: screen 3 added (80x25, vt100 emulation)
wsdisplay0: screen 4 added (80x25, vt100 emulation)
wsdisplay0: screen 5 added (80x25, vt100 emulation)
wsdisplay0: screen 6 added (80x25, vt100 emulation)
wsdisplay0: screen 7 added (80x25, vt100 emulation)