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=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 9625DC433E2 for ; Fri, 4 Sep 2020 15:39:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76F8420770 for ; Fri, 4 Sep 2020 15:39:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726272AbgIDPjR (ORCPT ); Fri, 4 Sep 2020 11:39:17 -0400 Received: from relay3-d.mail.gandi.net ([217.70.183.195]:56707 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725984AbgIDPjQ (ORCPT ); Fri, 4 Sep 2020 11:39:16 -0400 X-Originating-IP: 90.66.108.79 Received: from localhost (lfbn-lyo-1-1932-79.w90-66.abo.wanadoo.fr [90.66.108.79]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id 5FF9F60012; Fri, 4 Sep 2020 15:39:13 +0000 (UTC) Date: Fri, 4 Sep 2020 17:39:13 +0200 From: Alexandre Belloni To: Bartosz Golaszewski Cc: Alessandro Zummo , linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: Re: [PATCH 5/8] rtc: rx8010: don't use magic values for time buffer length Message-ID: <20200904153913.GK230586@piout.net> References: <20200904152116.2157-1-brgl@bgdev.pl> <20200904152116.2157-6-brgl@bgdev.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200904152116.2157-6-brgl@bgdev.pl> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/09/2020 17:21:13+0200, Bartosz Golaszewski wrote: > From: Bartosz Golaszewski > > The time buffer len is used directly in this driver. For readability > it's better to define a constant. > > Signed-off-by: Bartosz Golaszewski > --- > drivers/rtc/rtc-rx8010.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/rtc/rtc-rx8010.c b/drivers/rtc/rtc-rx8010.c > index 67ff06a76629..f3bed7be2533 100644 > --- a/drivers/rtc/rtc-rx8010.c > +++ b/drivers/rtc/rtc-rx8010.c > @@ -48,6 +48,8 @@ > > #define RX8010_ALARM_AE BIT(7) > > +#define RX8010_TIME_BUF_LEN 7 > + > static const struct i2c_device_id rx8010_id[] = { > { "rx8010", 0 }, > { } > @@ -108,7 +110,7 @@ static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id) > static int rx8010_get_time(struct device *dev, struct rtc_time *dt) > { > struct rx8010_data *rx8010 = dev_get_drvdata(dev); > - u8 date[7]; I'm usually fine with a magic value here... > + u8 date[RX8010_TIME_BUF_LEN]; > int flagreg, err; > > flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG); > @@ -121,8 +123,8 @@ static int rx8010_get_time(struct device *dev, struct rtc_time *dt) > } > > err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC, > - 7, date); > - if (err != 7) > + RX8010_TIME_BUF_LEN, date); ..as long as sizeof(date) is used here. Even better, you could have date[RX8010_YEAR - RX8010_SEC + 1] and then use sizeof. Or also have #define RX8010_TIME_BUF_LEN (RX8010_YEAR - RX8010_SEC + 1) which would be safer than 7. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com