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From: Arvid Brodin <Arvid.Brodin@xdin.com>
To: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Subject: Do I need to skb_put() Ethernet frames to a minimum of 60 bytes?
Date: Tue, 14 Aug 2012 18:53:57 +0000	[thread overview]
Message-ID: <502A9EC4.4040208@xdin.com> (raw)

Hi,

If I create an sk_buff with a payload of less than 28 bytes (ethheader + data),
and send it using the cadence/macb (Ethernet) driver, I get

eth0: TX underrun, resetting buffers

Now I know the minimum Ethernet frame size is 64 bytes (including the 4-byte
FCS), but whose responsibility is it to pad the frame to this size if necessary?
Mine or the driver's - i.e. should I just skb_put() to the minimum size or
should I report the underrun as a driver bug?


-- 
Arvid Brodin | Consultant (Linux)
XDIN AB | Jan Stenbecks Torg 17 | SE-164 40 Kista | Sweden | xdin.com

             reply	other threads:[~2012-08-14 19:04 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-14 18:53 Arvid Brodin [this message]
2012-08-14 20:35 ` Do I need to skb_put() Ethernet frames to a minimum of 60 bytes? Ben Hutchings
2012-08-21 17:34   ` Arvid Brodin
2012-08-21 17:42     ` Eric Dumazet
2012-08-21 18:07     ` Ben Hutchings
2012-12-17 13:43     ` Nicolas Ferre
2012-12-17 13:43       ` Nicolas Ferre
2012-12-17 15:15       ` Arvid Brodin
2012-12-17 15:15         ` Arvid Brodin

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