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From: David Miller <davem@davemloft.net>
Subject: Re: [RFC] New Qlogic 10Gb Ethernet driver for 2.6.28
Date: Mon, 25 Aug 2008 14:05:22 -0700 (PDT)
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From: Ron Mercer <ron.mercer@qlogic.com>
Date: Mon, 25 Aug 2008 10:01:48 -0700

> I see your point.  I will add the re-alignment but would like to jump
> over it for platforms that don't need it.  Is there a list somewhere of
> the RISC platforms that take a trap on unaligned accesses?  Or better
> yet, a list of those that don't?

If you're only doing this for the header portion it's not so
much of a cost.  For sizable packets you're using page
references, and you don't have to copy those, such copies
of the headers will also warm up the CPU cache as a nice
side effect.

Furthermore you stated that the alignment restriction only
is necessary for early revisions of the hardware.

Please, I do not want to give you a list of platform names
to ifdef up your driver with, that's messy.  Just make the
copy when necessary to align things properly.