From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sascha Hauer Subject: Re: [rtc-linux] [PATCH 2/2] rtc: mediatek: Add MT63xx RTC driver Date: Fri, 13 Mar 2015 11:57:42 +0100 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 Return-path: Content-Disposition: inline In-Reply-To: <1426242563.18291.19.camel@mtksdaap41> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eddie Huang Cc: Andrew Morton , Mark Rutland , Alessandro Zummo , srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, Pawel Moll , Ian Campbell , rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, yh.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tianping Fang , Grant Likely , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Rob Herring , linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Sascha Hauer , Kumar Gala , Matthias Brugger , yingjoe.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@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 | -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html