Re: [PATCH net v1] Revert "lan743x: trim all 4 bytes of the FCS; not just 2"

From: George McCollister
Date: Thu Apr 08 2021 - 14:00:54 EST


On Thu, Apr 8, 2021 at 12:46 PM Sven Van Asbroeck <thesven73@xxxxxxxxx> wrote:
>
> Hi George,
>
> On Thu, Apr 8, 2021 at 1:36 PM George McCollister
> <george.mccollister@xxxxxxxxx> wrote:
> >
> > Can you explain the difference in behavior with what I was observing
> > on the LAN7431?
>
> I'm not using DSA in my application, so I cannot test or replicate
> what you were observing. It would be great if we could work together
> and settle on a solution that is acceptable to both of us.

Sounds good.

>
> > I'll retest but if this is reverted I'm going to start
> > seeing 2 extra bytes on the end of frames and it's going to break DSA
> > with the LAN7431 again.
> >
>
> Seen from my point of view, your patch is a regression. But perhaps my
> patch set is a regression for you? Catch 22...
>
> Would you be able to identify which patch broke your DSA behaviour?
> Was it one of mine? Perhaps we can start from there.

Yes, first I'm going to confirm that what is in the net branch still
works (unlikely but perhaps something else could have broken it since
last I tried it).
Then I'll confirm the patch which I believe broke it actually did and
report back.

>
> Sven