Re: [PATCH net v2 2/3] net: stmmac: dwmac1000: don't discard frames with only a checksum error

[Christian Schmidbauer]

Replying to the Sashiko review [1]:

> Suppose the MAC sets ES on an oversized frame with a valid FCS only
> because of bit 7. Is that frame still dropped here?

No. In threshold Rx mode it reaches the stack if it fits one Rx buffer.
It is marked CHECKSUM_UNNECESSARY only when Rx COE is on and the
engine reported no error for it.

> The giant-frame status is also no longer recorded anywhere.
> [...]
> Could the status parser be told what bit 7 means (Rx COE enabled and
> its type, ATDS or advanced timestamping)? Then bit 7 could be part of
> the mask whenever it means Giant Frame.

Dropping or counting such a frame needs a new argument for the
rx_status callback, which all four descriptor implementations and both
Rx paths use. I would rather not change that interface in a fix for
net in order to drop an intact frame, and I have no testing hardware
on which bit 7 reports a giant frame.

[1] https://netdev-ai.bots.linux.dev/sashiko/#/message/20261104151914.2651241-3-opensource%40grische.xyz