NetBSD 9.0 not properly configuring NIC

[Rocky Hotas <rockyhotas%firemail.cc@localhost>]

Hi all!
I tried to install NetBSD 9.0 on a machine with motherboard Asus M2N-MX
SE Plus. Its integrated NIC is (from `pcictl pci0 list')

NVIDIA nForce MCP61 Gigabit Ethernet Controller (miscellaneous bridge, 
revision 0xa2)

which uses nfe(4) and atphy(4).

When I power on the system, the NIC LED is on. Then, I load the 9.0
installation kernel from the DVD and when the kernel messages show
the configuration of the first disk, wd0, the NIC LED turns off. It
never turns on back, even if I shutdown the system and power it on
again. The effect, from the user perspective, is that device `nfe0' is
perfectly working, but it has `no carrier', as if the Ethernet cable was
disconnected (but it is not; it is not a faulty cable, I checked. It's
connected to a channel of a swith, whose LED, in the switch side, is 
on).

In order for the NIC LED to turn on again, I must physically disconnect
power from the motherboard.

NetBSD 8.1 perfectly worked on the same machine. The only way to make
9.0 work is: disconnect the motherboard from power, reconnect the power,
boot with NetBSD 8.1, and then boot with 9.0 installation. This way,
the NetBSD 8.1 configurationis someway kept, and 9.0 is able to normally
work. But if, for some reason, power from the motherboard is 
disconnected
again, and NetBSD 9.0 is the first OS to boot, the NIC LED issue appears
again as above.

Apparently, since 31st May, 2019 (NetBSD 8.1 build date), several
modifications have been made to nfe(4) and atphy(4); maybe them, and
maybe along with other pci code modifications, are responsible for this.

I would like to signal this issue. We always wish that updates are
improvements, and in this case it is not.

To further trace this problem, I tested 5 different kernels:

- 8.1 		(dmesg: https://pastebin.com/LXv6sBdh, `ifconfig -a': 
https://pastebin.com/Q1qK270Z)
- netbsd-8	(dmesg: https://pastebin.com/vxzsjNmK, `ifconfig -a': 
https://pastebin.com/PKmwYp9g)
- 9.0		(dmesg: https://pastebin.com/rN5pfRMr, `ifconfig -a': 
https://pastebin.com/gLaWND2Z)
- netbsd-9	(dmesg: https://pastebin.com/ApW1Jm9E, `ifconfig -a': 
https://pastebin.com/XStVtk4a)
- current	(dmesg: https://pastebin.com/XujFbHZB, `ifconfig -a': 
https://pastebin.com/EC7041L8)

`netbsd-8' behaves like `8.1'; `netbsd-9' and `current' behave like 
`9.0'.

Bye!

Rocky


P. S.
Note that 9.0 is the kernel of an installed NetBSD; all the other are
the installation kernels. As regards 9.0, from the perspective of this
NIC issue, the installation kernel and the kernel of the installed 
system
behave the same way.