From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754338AbbCMK56 (ORCPT ); Fri, 13 Mar 2015 06:57:58 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:41332 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752541AbbCMK54 (ORCPT ); Fri, 13 Mar 2015 06:57:56 -0400 Date: Fri, 13 Mar 2015 11:57:42 +0100 From: Sascha Hauer To: Eddie Huang Cc: Andrew Morton , Mark Rutland , Alessandro Zummo , srv_heupstream@mediatek.com, Pawel Moll , Ian Campbell , rtc-linux@googlegroups.com, yh.chen@mediatek.com, linux-kernel@vger.kernel.org, Tianping Fang , Grant Likely , devicetree@vger.kernel.org, Rob Herring , linux-mediatek@lists.infradead.org, Sascha Hauer , Kumar Gala , Matthias Brugger , yingjoe.chen@mediatek.com, linux-arm-kernel@lists.infradead.org Subject: Re: [rtc-linux] [PATCH 2/2] rtc: mediatek: Add MT63xx RTC driver Message-ID: <20150313105742.GS24885@pengutronix.de> References: <1422437276-41334-1-git-send-email-eddie.huang@mediatek.com> <1422437276-41334-3-git-send-email-eddie.huang@mediatek.com> <20150223135044.108ea32a65063a50aa36a309@linux-foundation.org> <1426242563.18291.19.camel@mtksdaap41> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1426242563.18291.19.camel@mtksdaap41> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 11:44:49 up 4 days, 2:06, 61 users, load average: 0.08, 0.05, 0.11 User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Eddie, On Fri, Mar 13, 2015 at 06:29:23PM +0800, Eddie Huang wrote: > > regmap_read() and regmap_write() can return errors. There is no > > checking for this. > > > > I encounter some trouble when I add code to check return value of > regmap_read and regmap_write. Every RTC register access through regmap, > and there are many register read/write in this driver. If I check every > return value, the driver will become ugly. I try to make this driver > clean using following macro. > > static int __rtc_read(struct mt6397_rtc *rtc, u32 offset, u32 *data) > { > u32 addr = rtc->addr_base + offset; > > if (offset < rtc->addr_range) > return regmap_read(rtc->regmap, addr, data); > > return -EINVAL; > } > > #define rtc_read(ret, rtc, offset, data) \ > ({ \ > ret = __rtc_read(rtc, offset, data); \ > if (ret < 0) \ > goto rtc_exit; \ > }) \ Hiding a goto (or return) in a macro is a very bad idea. what you can do is ret |= regmap_read(rtc->regmap, RTC_TC_SEC, &tm->tm_sec); ret |= regmap_read(rtc->regmap, RTC_TC_MIN, &tm->tm_min); if (ret) return -EIO; (Don't return ret in this case though as it might contain different error codes orred together) Another possibilty at least for contiguous registers would be regmap_bulk_read(). Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |