From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5733DC43219 for ; Tue, 30 Apr 2019 10:52:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2F8F121707 for ; Tue, 30 Apr 2019 10:52:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727419AbfD3KwV convert rfc822-to-8bit (ORCPT ); Tue, 30 Apr 2019 06:52:21 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([146.101.78.151]:41503 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727333AbfD3KwR (ORCPT ); Tue, 30 Apr 2019 06:52:17 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-219-o3Z4AmsVPhKcl9wCrASykQ-1; Tue, 30 Apr 2019 11:52:14 +0100 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b::d117) by AcuMS.aculab.com (fd9f:af1c:a25b::d117) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Tue, 30 Apr 2019 11:52:13 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Tue, 30 Apr 2019 11:52:13 +0100 From: David Laight To: 'Phong Tran' , "robh+dt@kernel.org" , "frowand.list@gmail.com" , "pantelis.antoniou@konsulko.com" CC: "natechancellor@gmail.com" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] of: replace be32_to_cpu to be32_to_cpup Thread-Topic: [PATCH] of: replace be32_to_cpu to be32_to_cpup Thread-Index: AQHU/zOHQCFPeP9s40qeT2QsFKHyGqZUhhqA Date: Tue, 30 Apr 2019 10:52:13 +0000 Message-ID: <46b3e8edf27e4c8f98697f9e7f2117d6@AcuMS.aculab.com> References: <20190430090044.16345-1-tranmanphong@gmail.com> In-Reply-To: <20190430090044.16345-1-tranmanphong@gmail.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-MC-Unique: o3Z4AmsVPhKcl9wCrASykQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Phong Tran > Sent: 30 April 2019 10:01 > The cell is a pointer to __be32. > with the be32_to_cpu a lot of clang warning show that: > > ./include/linux/of.h:238:37: warning: multiple unsequenced modifications > to 'cell' [-Wunsequenced] > r = (r << 32) | be32_to_cpu(*(cell++)); > ^~ > ./include/linux/byteorder/generic.h:95:21: note: expanded from macro > 'be32_to_cpu' > ^ > ./include/uapi/linux/byteorder/little_endian.h:40:59: note: expanded > from macro '__be32_to_cpu' > ^ > ./include/uapi/linux/swab.h:118:21: note: expanded from macro '__swab32' > ___constant_swab32(x) : \ > ^ > ./include/uapi/linux/swab.h:18:12: note: expanded from macro > '___constant_swab32' > (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \ > ^ > > Signed-off-by: Phong Tran > --- > include/linux/of.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/of.h b/include/linux/of.h > index e240992e5cb6..1c35fc8f19b0 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -235,7 +235,7 @@ static inline u64 of_read_number(const __be32 *cell, int size) > { > u64 r = 0; > while (size--) > - r = (r << 32) | be32_to_cpu(*(cell++)); > + r = (r << 32) | be32_to_cpup(cell++); > return r; That is a very strange loop. It is probably equivalent to: r = be32_to_cpu(*cell); if (size) r = r << 32 | be32_to_cpu(cell[1]); return r; In any case replacing the while with (say): for (; size--; cell++) r = (r << 32) | be32_to_cpu(*cell); would remove the ambiguity. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)