From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755241Ab2DCQSH (ORCPT ); Tue, 3 Apr 2012 12:18:07 -0400 Received: from mail.vyatta.com ([76.74.103.46]:34981 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754641Ab2DCQSF (ORCPT ); Tue, 3 Apr 2012 12:18:05 -0400 Date: Tue, 3 Apr 2012 09:17:50 -0700 From: Stephen Hemminger To: Chris Metcalf Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] marvell sky2 driver: fix so it works without unaligned accesses Message-ID: <20120403091750.11eff45b@s6510.linuxnetplumber.net> In-Reply-To: <201204031527.q33FR04i031747@farm-0027.internal.tilera.com> References: <201204031527.q33FR04i031747@farm-0027.internal.tilera.com> Organization: Vyatta X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 3 Apr 2012 11:13:56 -0400 Chris Metcalf wrote: > The driver uses a receive_new() routine that ends up requiring unaligned > accesses in IP header processing. If the architecture doesn't support > efficient unaligned accesses, just copy all ingress packets to the bounce > buffers instead. > > This allows the driver to be used on the Tilera TILEmpower-Gx, since > the tile architecture doesn't currently handle kernel unaligned accesses, > just userspace. > > Signed-off-by: Chris Metcalf There are many other encapsulation cases where IP header won't be aligned. Why not just set copybreak module option to a very large value?