miibus and fxp motherboard devices

[Richard P. Williamson]

Hello, 

I've got a pentium SBC with three on-board fxp lan devices.

In my 4.8 kernel config, I've got 
device   miibus
device   fxp

The dmesg has this to say about the devices:

fxp0: <Intel Pro 10/100B/100+ Ethernet> port 0xd800-0xd83f mem 0xe5000000-0xe50fffff,0xe5300000-0xe5300fff irq 12 at device 8.0 on pci0
fxp0: Ethernet address 00:30:64:01:86:ff, 10Mbps
fxp1: <Intel Pro 10/100B/100+ Ethernet> port 0xdc00-0xdc3f mem 0xe5100000-0xe51fffff,0xe5302000-0xe5302fff irq 10 at device 9.0 on pci0
fxp1: Ethernet address 00:30:64:01:94:00, 10Mbps
fxp2: <Intel Pro 10/100B/100+ Ethernet> port 0xe000-0xe03f mem 0xe5200000-0xe52fffff,0xe5301000-0xe5301fff irq 11 at device 10.0 on pci0
fxp2: Ethernet address 00:30:64:01:94:01, 10Mbps

Specifically, it has nothing to say about the miibus.  Compare this
to the dmesg on a pentium desktop with a dual-fxp PCI card (and
devices miibus and fxp in its config):

fxp0: <Intel Pro 10/100B/100+ Ethernet> port 0xc000-0xc01f mem 0xdf000000-0xdf0fffff,0xe0000000-0xe0000fff irq 12 at device 4.0 on pci2
fxp0: Ethernet address 00:03:47:3b:f3:f4
inphy0: <i82555 10/100 media interface> on miibus0
inphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
fxp1: <Intel Pro 10/100B/100+ Ethernet> port 0xc400-0xc41f mem 0xdf100000-0xdf1fffff,0xe0001000-0xe0001fff irq 10 at device 5.0 on pci2
fxp1: Ethernet address 00:03:47:3b:f3:f5
inphy1: <i82555 10/100 media interface> on miibus1
inphy1:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto

At the moment, I can not swap the SCB fxp devices out of 10Mb
mode and into any of the others that the devices (putatively) 
support.  

If I plug the dual-fxp PCI card into the SBC's pci bus, then 
I get fxp3 and fxp4, each of which are 10baseT, 10baseT-FDX,
100baseTX, 100baseTX-FDX and auto capable.

I'd welcome any suggestions about how to enable the additional
modes on the motherboard lan parts.  Even if it is specific
keywords to do a google on (the ones I've chosen insist on 
showing me other peoples' dmesgs).  

Am I missing something in my kernel config?

rip