Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755316Ab2JRJy6 (ORCPT ); Thu, 18 Oct 2012 05:54:58 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:44105 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755275Ab2JRJy4 (ORCPT ); Thu, 18 Oct 2012 05:54:56 -0400 Date: Thu, 18 Oct 2012 10:59:56 +0100 From: Alan Cox To: Jeffrey Ladouceur Cc: Mark Einon , devel@driverdev.osuosl.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] staging: et131x: Fix 64bit tx dma address handling Message-ID: <20121018105956.2f3ea239@pyramind.ukuu.org.uk> In-Reply-To: References: <1350508512-15562-1-git-send-email-mark.einon@gmail.com> <1350508512-15562-2-git-send-email-mark.einon@gmail.com> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 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 Content-Length: 984 Lines: 25 > > + skb_headlen(skb), > > + DMA_TO_DEVICE); > > + desc[frag].addr_lo = dma_addr & 0xFFFFFFFF; > > + desc[frag].addr_hi = dma_addr >> 32; > > Maybe use macros defined in kernel.h instead: > > desc[frag].addr_lo = lower_32_bits(dma_addr); > desc[frag].addr_hi = upper_32_bits(dma_addr); > > A few more instances below. This is actually important because >> 32 of a 32bit value is undefined in C. The compiler is free to do what it likes with this. While the results are usually sane some architectures do generate the equivalent of x >> (n % wordsize); Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/