Regression with AX88179A: can't manually set MAC address anymore

[Sergio Callegari <sergio.callegari@gmail.com>]

Hi, reporting here as the issue I am seeing is cross distro and relevant 
to recent kernels. Hope this is appropriate.

I have a USB hub with AX88179A ethernet. I was able to use it regularly, 
until something changed in recent kernels to have this interface 
supported by the cdc_ncm driver. After this change it is not possible 
anymore to work with a manually set MAC address.

More details:

- before the kernel changes, the interface was supported by a dedicated 
kernel driver. The driver had glitches but was more or less working. The 
main issue was that after some usage the driver stopped working. Could 
fix these glitches with the driver at 
https://github.com/nothingstopsme/AX88179_178A_Linux_Driver

- after the kernel changes, loading the ax88179_178a.ko does not create 
a network device anymore. The interface can be used with the cdc_ncm 
driver, however it is not possible anymore to use a manually set MAC 
address.

When you manually set a MAC this appears to be accepted (e.g. ip link 
reports it correctly), but the card does not receive data anymore. For 
instance, trying to connect to a DHCP server, you see that the server 
receives the request, makes an offer, but the offer is never received by 
the network card.

This may be the same issue reported here: 
https://discussion.fedoraproject.org/t/ax88179-178a-network-fails-to-start-usb-to-eth/77687 
where the user says he cannot use the adapter when Network Manager is 
configured to employ a randomized MAC address.

Would be great to have this regression fixed or at least to have the 
command setting the MAC address erroring out properly.

Thanks for the attention.

Sergio Callegari