From: David Miller <davem@davemloft.net>
To: peppe.cavallaro@st.com
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH] net: fix unaligned memory accesses in ASIX
Date: Thu, 26 Mar 2009 02:00:18 -0700 (PDT) [thread overview]
Message-ID: <20090326.020018.26561577.davem@davemloft.net> (raw)
In-Reply-To: <49CB3F6D.2010508@st.com>
From: Giuseppe CAVALLARO <peppe.cavallaro@st.com>
Date: Thu, 26 Mar 2009 09:40:13 +0100
> Unfortunately, unaligned memory accesses seems to depend on the Asix HW
> that packs several incoming frames.
> So when these frames are 'unpacked' within the fix-up function, and
> pushed to the upper layer, they can have a wrong alignment, indeed.
> When no frame is packed all works fine and the IP never works with
> unaligned addresses.
> I think, the skb_reserve could actually help us, if this last scenario
> generated misaligned accesses.
> Please let me know if I'm missing something.
The unpacker is taking a set of packet(s) in a USB buffer
and copying them into SKB's right? That code should be where
the offset is checked in the child driver, and adjustments
made as-needed.
This code seems to call the downstream driver callback after
the damage is done. I think it needs to ask the driver to
look for and indicate the offset before the building of the
SKB is performed.
next prev parent reply other threads:[~2009-03-26 9:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-26 6:52 [PATCH] net: fix unaligned memory accesses in ASIX Giuseppe CAVALLARO
2009-03-26 8:08 ` David Miller
2009-03-26 8:40 ` Giuseppe CAVALLARO
2009-03-26 9:00 ` David Miller [this message]
2009-03-26 10:01 ` Giuseppe CAVALLARO
2009-04-15 10:14 ` David Miller
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