Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752481AbbHEJL1 (ORCPT ); Wed, 5 Aug 2015 05:11:27 -0400 Received: from mail-out.m-online.net ([212.18.0.10]:36504 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751073AbbHEJLZ (ORCPT ); Wed, 5 Aug 2015 05:11:25 -0400 X-Auth-Info: pgwZ0hBEQApdDMymlmVhoCF31Gzxesep8zeBu24X5E4= From: Marek Vasut To: Michal Suchanek Subject: Re: [PATCH v2 1/6] mtd: spi-nor: change return value of read/write Date: Wed, 5 Aug 2015 11:11:20 +0200 User-Agent: KMail/1.13.7 (Linux/3.14-2-amd64; KDE/4.13.1; x86_64; ; ) Cc: David Woodhouse , Brian Norris , Han Xu , =?utf-8?q?Rafa=C5=82_Mi=C5=82ecki?= , Huang Shijie , Ben Hutchings , Gabor Juhos , Bean Huo =?utf-8?q?=E9=9C=8D=E6=96=8C=E6=96=8C?= , MTD Maling List , Linux Kernel Mailing List , Hou Zhiqiang , Huang Shijie References: <201508041842.03871.marex@denx.de> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201508051111.21068.marex@denx.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2939 Lines: 72 On Wednesday, August 05, 2015 at 10:27:05 AM, Michal Suchanek wrote: > On 4 August 2015 at 18:42, Marek Vasut wrote: > > On Tuesday, August 04, 2015 at 08:42:51 AM, Michal Suchanek wrote: > >> On 3 August 2015 at 23:46, Marek Vasut wrote: > >> > On Monday, August 03, 2015 at 08:39:01 PM, Michal Suchanek wrote: > >> >> Change the return value of spi-nor device read and write methods to > >> >> allow returning amount of data transferred and errors as > >> >> read(2)/write(2) does. > >> >> > >> >> Signed-off-by: Michal Suchanek > >> >> --- > >> >> > >> >> include/linux/mtd/spi-nor.h | 4 ++-- > >> >> 1 file changed, 2 insertions(+), 2 deletions(-) > >> >> > >> >> diff --git a/include/linux/mtd/spi-nor.h > >> >> b/include/linux/mtd/spi-nor.h index e540952..7d782cb 100644 > >> >> --- a/include/linux/mtd/spi-nor.h > >> >> +++ b/include/linux/mtd/spi-nor.h > >> >> @@ -185,9 +185,9 @@ struct spi_nor { > >> >> > >> >> int (*write_reg)(struct spi_nor *nor, u8 opcode, u8 *buf, int > >> >> len, > >> >> > >> >> int write_enable); > >> >> > >> >> - int (*read)(struct spi_nor *nor, loff_t from, > >> >> + ssize_t (*read)(struct spi_nor *nor, loff_t from, > >> >> > >> >> size_t len, size_t *retlen, u_char *read_buf); > >> >> > >> >> - void (*write)(struct spi_nor *nor, loff_t to, > >> >> + ssize_t (*write)(struct spi_nor *nor, loff_t to, > >> >> > >> >> size_t len, size_t *retlen, const u_char > >> >> *write_buf); > >> >> > >> >> int (*erase)(struct spi_nor *nor, loff_t offs); > >> > > >> > You realize that if someone does bisect and has only this patch > >> > applied, the compiler will complain loudly about mismatching data > >> > types, right ? > >> > > >> > :) > >> > >> Yes, the compiler prints a warning. However, only the return value > >> which is not used changes so it should not cause any real problem. > > > > Are you certain that ssize_t is equal to int , always , everywhere ? :-) > > No, it's larger or equal. Not per any standard to my knowledge, but yeah. I don't think it's a good idea to do this change alone. > > Note that it is possible to do such conversion even without introducing > > compiler warnings along the way -- just do the data type conversion first > > and the other changes in subsequent patches. It will be clear that one > > patch does one thing then. > > If this is the only concern with these patches it is easily amended ;-) It'd be nice if the others reviewed it as well, additional feedback would be nice. Best regards, Marek Vasut -- 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/