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From: David Oostdyk <daveo@ll•mit.edu>
To: <netdev@vger•kernel.org>
Cc: <macro@linux-mips•org>
Subject: defxx: skb_push() failing?
Date: Tue, 26 Mar 2013 10:29:34 -0400	[thread overview]
Message-ID: <5151B0CE.5000000@ll.mit.edu> (raw)

Hello,

In dfx_xmt_queue_pkt() in defxx.c, there is a skb_push(3) call which 
makes room for 3 packet request header bytes.  There is some discussion 
in the driver explaining why those three bytes will be available.  I 
have an old FDDI card that I'm trying to bring up:

05:05.0 FDDI network controller: Digital Equipment Corporation 
PCI-to-PDQ Interface Chip [PFI] (rev 02)

Most skbuffs that come through dfx_xmit_queue_pkt() have 11 bytes 
between skb->head and skb->data.  On the other hand, at almost exactly 
60-second intervals, an skb arrives that has zero bytes between 
skb->head and skb->data.  This normally causes a kernel panic, and for 
the time I just skip over such skb's.

Does anyone have advice on where I should start digging to find the 
cause of this?

Thanks in advance!
- David Oostdyk

             reply	other threads:[~2013-03-26 14:29 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-26 14:29 David Oostdyk [this message]
2013-03-26 15:15 ` defxx: skb_push() failing? Eric Dumazet
2013-03-26 16:03   ` David Oostdyk
2013-03-26 16:30     ` Eric Dumazet
2013-03-26 18:45       ` David Oostdyk
2013-03-26 19:00         ` Maciej W. Rozycki
2013-03-28  4:11           ` David Oostdyk
2013-03-28  4:28             ` [PATCH] aoe: reserve enough headroom on skbs Eric Dumazet
2013-03-28 18:30               ` David Miller

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