It seems axe(4) controllers support interrupt endpoint such that
enabling interrupt endpoint generates about 1000 interrupts/sec.
Controllers transfer 8 bytes data through interrupt endpoint and
the data include link UP/DOWN state as well as some PHY related
information. Previously axe(4) didn't use the transferred data and
didn't even try to read the data. Because axe(4) counts on mii(4)
to detect link state changes there is no need to use interrupt
endpoint here.
This change fixes generation of unnecessary interrupts which was
seen when interface is brought to UP.
No objections from: hselasky
f95779d97e