Re: [PATCH net-next] net: ag71xx: align the IP header behind DSA tags

[Rosen Penev]

On Fri, Oct 9, 2026 at 3:27 PM Rosen Penev <rosenp@xxxxxxxxx> wrote:
>
> On Fri, Oct 9, 2026 at 9:47 AM Simon Horman <horms@xxxxxxxxxx> wrote:
> >
> > On Wed, Oct 07, 2026 at 10:44:49AM -0700, Rosen Penev wrote:
> > > The receive buffer offset includes NET_IP_ALIGN to get the IP header
> > > aligned behind a 14 byte Ethernet header. Most ag71xx devices use DSA
> > > switches whose tag sits in front of the EtherType, which moves the IP
> > > header by another 2 bytes. Every access to the IP and TCP headers then
> > > traps and gets emulated by the unaligned access handler, around 6 times
> > > per forwarded frame.
> > >
> > > Take the headroom needed by the DSA tagger into account when choosing
> > > the offset.
> > >
> > > TP-Link Archer C7 v2 (qca8k), median of 3 runs, Mbit/s:
> > >
> > >                        before   after
> > >   routed up               743     855
> > >   routed down             660     749
> > >   local receive           554     572
> > >
> > > The unaligned instruction counter no longer moves while forwarding.
> > >
> > > Assisted-by: LLM
> > > Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
> >
> > Unfortunately this patch did not apply cleanly to net-next at the time it
> > was posted, so our CI did not run.
> It appears I was careless and sent it ahead of local commits. Will resend.
I see the issue

A different patch removes the comment:

For our NAPI weight bigger does *NOT* mean better - it means more

so git am fails but git apply works.
> >
> > Please rebase and repost.
> >
> > --
> > pw-bot: changes-requested