Problem with Orange Pi 5 ethernet PHY on NetBSD 11

[John Klos <john%klos.com@localhost>]

Hi, all,

So far NetBSD 11 on my various Arm systems has been quite happy.

I did notice an issue with ethernet on my Orange Pi 5 running UEFI v1.1 
(edk2-rk3588). Ethernet works fine in NetBSD 10, but with NetBSD 11 the 
interface can be configured and shows link, but it doesn't communicate.

If I create an arp entry on another machine, packets will be received by 
the Orange Pi. tcpdump shows the Pi thinks it's sending responses, but 
they never make it on to the wire.

If I configure another interface on the same network, then bring up eqos0 
with the same subnet, then manually create an arp entry elsewhere, packets 
will come in, and return packets will go out of the other ethernet 
interface, at least as long as the arp entry exists.

What's changed is that in NetBSD 10, the interface configured like this:

[     1.000004] eqos0 at acpi0 (MAC1, RKCP6543-61): mem 0xfe1c0000-0xfe1cffff irq 266,265
[     1.000004] eqos0: DesignWare EQOS ver 0x51 (0x30)
[     1.000004] eqos0: hw features 1a1173f7 111e01e8 11041041 0c370031
[     1.000004] eqos0: using 32-bit DMA
[     1.000004] eqos0: Ethernet address 0e:f5:d1:ce:56:d0
[     1.000004] ukphy0 at eqos0 phy 0: OUI 0xc82b5e, model 0x0011, rev. 11
[     1.000004] ukphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT-FDX, auto
[     1.000004] ukphy1 at eqos0 phy 1: OUI 0xc82b5e, model 0x0011, rev. 11
[     1.000004] ukphy1: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT-FDX, auto

whereas in NetBSD 11, we get mcommphy* PHYs:

[     1.000004] mcommphy0 at eqos0 phy 0: Motorcomm YT8531 GbE PHY
[     1.000004] mcommphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT-FDX, auto
[     1.000004] mcommphy1 at eqos0 phy 1: Motorcomm YT8531 GbE PHY
[     1.000004] mcommphy1: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT-FDX, auto

Compiling a GENERIC64 kernel with mcommphy* commented results in working 
ethernet.

Ideas?

Thanks!
John Klos