Return-path: Received: from py-out-1112.google.com ([64.233.166.179]:36467 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755914AbYCTOjK (ORCPT ); Thu, 20 Mar 2008 10:39:10 -0400 Received: by py-out-1112.google.com with SMTP id u52so1269689pyb.10 for ; Thu, 20 Mar 2008 07:39:08 -0700 (PDT) Message-ID: <87a5b0800803200739v6d222afck850f221eae1edd70@mail.gmail.com> (sfid-20080320_143915_124685_4EA0E077) Date: Thu, 20 Mar 2008 14:39:08 +0000 From: "Will Newton" To: "Johannes Berg" Subject: Re: [PATCH/RFC] introduce ARCH_CAN_UNALIGNED_ACCESS Kconfig symbol Cc: "Daniel Drake" , "Linux Kernel list" , linux-wireless , netdev In-Reply-To: <1206023695.16475.137.camel@johannes.berg> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <1206023695.16475.137.camel@johannes.berg> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Mar 20, 2008 at 2:34 PM, Johannes Berg wrote: > +For some ethernet hardware that cannot DMA to unaligned addresses like > +4*n+2 or non-ethernet hardware, this can be a problem, and it is then > +required to copy the incoming frame into an aligned buffer. Because this is > +unnecessary on architectures that can do unaligned accesses, the code can be > +made depend on CONFIG_ARCH_CAN_UNALIGNED_ACCESS like so: > + > +#ifdef CONFIG_ARCH_CAN_UNALIGNED_ACCESS > + skb = copy skb > +#else > + skb = original skb > +#endif Is this logic reversed?