Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754778AbbETXpf (ORCPT ); Wed, 20 May 2015 19:45:35 -0400 Received: from mail-pd0-f174.google.com ([209.85.192.174]:33359 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753150AbbETXpa (ORCPT ); Wed, 20 May 2015 19:45:30 -0400 Date: Wed, 20 May 2015 16:45:25 -0700 From: Brian Norris To: Michal Suchanek Cc: David Woodhouse , zajec5@gmail.com, Marek Vasut , Alison Chaiken , Ben Hutchings , Geert Uytterhoeven , "Bean Huo (beanhuo)" , "grmoore@altera.com" , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] MTD: m25p80: fix write return value. Message-ID: <20150520234525.GY11598@ld-irv-0074> References: <02f7510acb9b6dbb3a5a6cd5bb287762eb4d22c1.1430430153.git.hramrach@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <02f7510acb9b6dbb3a5a6cd5bb287762eb4d22c1.1430430153.git.hramrach@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2305 Lines: 57 On Thu, Apr 30, 2015 at 03:33:47PM +0200, Michal Suchanek wrote: > The 'retlen' points to a variable representing the number of data bytes > written/read (see include/linux/mtd/mtd.h) by the current invocation of > the function. This variable must be set, not incremented. > > v2: clearer commit message > > Signed-off-by: Michal Suchanek > Acked-by: Marek Vasut > --- > drivers/mtd/devices/m25p80.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c > index 7c8b169..0b2bc21 100644 > --- a/drivers/mtd/devices/m25p80.c > +++ b/drivers/mtd/devices/m25p80.c > @@ -102,7 +102,7 @@ static void m25p80_write(struct spi_nor *nor, loff_t to, size_t len, > > spi_sync(spi, &m); > > - *retlen += m.actual_length - cmd_sz; > + *retlen = m.actual_length - cmd_sz; This is very wrong. It gets a little better once you add your next patches (which are also not good) since those patches reinterpret the usage of retlen, but this one definitely does *not* stand a lone. I'll admit the API is a little odd here, but the callers of this function (see spi_nor_write()) actually depend on calling this multiple times, with the value incrementing each time so we get a summary total. You're now clobbering this value. I'm willing to accept patches to improve this API, if you think that would help. Or to add comments that document this. > } > > static inline unsigned int m25p80_rx_nbits(struct spi_nor *nor) Also, I'm a little confused because you sent two different patch series very close to each other, and this patch is in both of them. Please don't do that. Either send a single patch series that contains all patches (and is versions v2, v3, etc., as you revise the whole thing) or send completely independent patch series. Don't include the same patch in different series. Anyway, please consider my comments, and when you have something better, please resend everything. I'm not going to take either series as-is. Thanks, Brian -- 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/