From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Wed, 7 Mar 2012 09:14:09 +0000 Subject: [PATCH] ARM: remove ixp2000 platform In-Reply-To: References: <1330450426-14639-1-git-send-email-robherring2@gmail.com> <201202281945.39419.arnd@arndb.de> <201203061412.00073.arnd@arndb.de> Message-ID: <20120307091409.GL17370@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Mar 07, 2012 at 09:40:31AM +0100, Linus Walleij wrote: > Network equipment seems to like using BE. > > I have some vague idea that this is beacuse IP packets are big > endian, and thus you can process them quickly by just casting fields > to e.g. u32 pointers and read them. > > I don't know if this is true, but seems to much of a correlation to > be pure coincidence. Thus a pretty interesting subject in > embedded ARM not used for tablets/mobile/generic computing > kind of stuff. ISTR Nicolas explained this to me as being an established thing in the comms sector. They expect BE and only understand BE. I did point out that you end up with many more endian conversions by going to BE, mainly because PCI is LE and all your PCI accesses have to be endian-swapped. So in terms of bandwidth, I'd expect an ARM PCI platform running in BE mode to have worse throughput than a LE PCI platform. But... if BE allows the comms people to keep their warm fuzzy feeling who are we to argue.