[PATCH net v2] net: stmmac: Clear DMA errors for multi-channel interrupts

[Magnus Leatti]

> Should the Fixes: tag point at 1b9707e6f1a9 instead, or also include it?
> As written, stable may backport this to 5.13+ trees that cannot hit these
> storms.

A data point for the RBU case from the YT6801, same 64-byte UDP RX
flood, all on the same 7.0.13 kernel:

  stmmac from 7.0.13 (has 6ccf12ae111e, not 1b9707e6f1a9):
    no storm; the MAC interrupt never fires (4 streams for 10 s,
    and 8 streams plus TX for 30 s)
  stmmac from 7.2.11, built for 7.0.13:
    storm, the machine hangs
  the same, with only 1b9707e6f1a9 reverted:
    no storm

So on this hardware the RBU storm needs 1b9707e6f1a9. I did not test
the RPS case.

> Since RBU and RPS were enabled only for statistics, was masking them in
> multi-MSI mode considered as an alternative?

For reference, d3265c19b35d ("net: stmmac: xgmac2: disable RBUE in
default RX interrupt mask") took that route for xgmac2.

Magnus