From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from webmail.solarflare.com ([12.187.104.25]:6773 "EHLO webmail.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753435Ab3HWMoi (ORCPT ); Fri, 23 Aug 2013 08:44:38 -0400 Message-ID: <1377261869.3364.3.camel@bwh-desktop.uk.level5networks.com> Subject: Re: [patch] net/fec: "u32" is more explicit than "unsigned long" From: Ben Hutchings Date: Fri, 23 Aug 2013 13:44:29 +0100 In-Reply-To: <20130823094920.GP31293@elgon.mountain> References: <20130823094920.GP31293@elgon.mountain> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: devicetree-owner@vger.kernel.org To: Dan Carpenter Cc: Grant Likely , Rob Herring , "David S. Miller" , Fabio Estevam , Frank Li , Jim Baxter , Fugang Duan , netdev@vger.kernel.org, devicetree@vger.kernel.org, kernel-janitors@vger.kernel.org List-ID: On Fri, 2013-08-23 at 12:49 +0300, Dan Carpenter wrote: > tmpaddr[] is a six byte array. We want to set the first four bytes on > the first line and the remaining two on the next line. The code assumes > that "unsigned long" is 32 bits and obviously that's not true on 64 bit > arches. It's better to just use u32 instead. > > Signed-off-by: Dan Carpenter > --- > This is a static checker thing and I can't compile this file. > > diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c > index fdf9307..422b125 100644 > --- a/drivers/net/ethernet/freescale/fec_main.c > +++ b/drivers/net/ethernet/freescale/fec_main.c > @@ -1100,9 +1100,9 @@ static void fec_get_mac(struct net_device *ndev) > * 4) FEC mac registers set by bootloader > */ > if (!is_valid_ether_addr(iap)) { > - *((unsigned long *) &tmpaddr[0]) = > + *((u32 *) &tmpaddr[0]) = > be32_to_cpu(readl(fep->hwp + FEC_ADDR_LOW)); > - *((unsigned short *) &tmpaddr[4]) = > + *((u16 *) &tmpaddr[4]) = > be16_to_cpu(readl(fep->hwp + FEC_ADDR_HIGH) >> 16); > iap = &tmpaddr[0]; > } This code also seems to have CPU vs big-endian byte order the wrong way round. readl() returns bytes in native order whereas we always store MAC addresses in network (big-endian) order. So I think it should be doing: *((__be32 *) &tmpaddr[0]) = cpu_to_be32(readl(fep->hwp + FEC_ADDR_LOW)); *((__be16 *) &tmpaddr[4]) = cpu_to_be16(readl(fep->hwp + FEC_ADDR_HIGH) >> 16); Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.