From: David Laight <david.laight.linux@gmail.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: "Nicolai Buchwitz" <nb@tipi-net.de>,
"Théo Lebrun" <theo.lebrun@bootlin.com>,
"Conor Dooley" <conor.dooley@microchip.com>,
"Claudiu Beznea" <claudiu.beznea@tuxon.dev>,
"Jonathan Bell" <jonathan@raspberrypi.com>,
"Andrew Lunn" <andrew+netdev@lunn.ch>,
"David S . Miller" <davem@davemloft.net>,
"Eric Dumazet" <edumazet@google.com>,
"Paolo Abeni" <pabeni@redhat.com>,
"Richard Cochran" <richardcochran@gmail.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net 1/2] net: macb: exclude software FCS from TX byte statistics
Date: Fri, 28 Aug 2026 09:37:06 +0100 [thread overview]
Message-ID: <20260828093706.3419d646@pumpkin> (raw)
In-Reply-To: <20260827115601.6bf0b18a@kernel.org>
On Thu, 27 Aug 2026 11:56:01 -0700
Jakub Kicinski <kuba@kernel.org> wrote:
> On Mon, 24 Aug 2026 15:47:02 +0200 Nicolai Buchwitz wrote:
> > + * @skb_len: skb->len as handed over by the stack, before padding and
> > + * software FCS, only set for the last buffer of the frame
>
> counting pad bytes to ETH_ZLEN as sent is perfectly legit,
> it's a driver preference. Some don't because HW pads and
> the driver doesn't want to bother adding a conditional.
> But it's best if the driver bytes match wire bytes IMO.
>
> Either way, you only need u8 or even a flag for this,
> not a full u32?
>
You could save a count to be subtracted from skb->len.
But isn't that also unrelated to the UDP checksum issue?
Note that the receiver will treat an IPv4 checksum of zero as valid.
For IPv6 it is a protocol error.
David
next prev parent reply other threads:[~2026-08-28 8:37 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-24 13:47 [PATCH net 0/2] net: macb: fix zero UDPv4 checksum on transmit Nicolai Buchwitz
2026-08-24 13:47 ` [PATCH net 1/2] net: macb: exclude software FCS from TX byte statistics Nicolai Buchwitz
2026-08-25 15:04 ` Nicolai Buchwitz
2026-08-27 8:52 ` Paolo Abeni
2026-08-28 8:10 ` Nicolai Buchwitz
2026-08-27 18:56 ` Jakub Kicinski
2026-08-28 8:20 ` Nicolai Buchwitz
2026-08-28 13:02 ` David Laight
2026-08-28 8:37 ` David Laight [this message]
2026-08-24 13:47 ` [PATCH net 2/2] net: macb: fix zero UDPv4 checksum on transmit Nicolai Buchwitz
2026-08-28 6:04 ` [PATCH net 0/2] " Alexander Dahl
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