PS: when I sent the above "net: stmmac: use per-queue 64 bit statistics
where necessary", I had an impression: there are too much statistics in
stmmac driver, I didn't see so many statistics in other eth drivers, is
it possible to remove some useless or not that useful statistic members?

These counters might be considered ABI. We don't want to cause
regressions in somebodies testing, or even billing scripts because we
remove a counter which somebody is using.

       Andrew