From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Laight Subject: RE: [PATCH] of: replace be32_to_cpu to be32_to_cpup Date: Tue, 30 Apr 2019 10:52:13 +0000 Message-ID: <46b3e8edf27e4c8f98697f9e7f2117d6@AcuMS.aculab.com> References: <20190430090044.16345-1-tranmanphong@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <20190430090044.16345-1-tranmanphong@gmail.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org 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" List-Id: devicetree@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)