Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751471AbdGZIXK (ORCPT ); Wed, 26 Jul 2017 04:23:10 -0400 Received: from mail-wr0-f173.google.com ([209.85.128.173]:38068 "EHLO mail-wr0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750922AbdGZIXI (ORCPT ); Wed, 26 Jul 2017 04:23:08 -0400 Date: Wed, 26 Jul 2017 09:23:04 +0100 From: Lee Jones To: Andy Shevchenko Cc: "Mani, Rajmohan" , "linux-kernel@vger.kernel.org" , "linux-gpio@vger.kernel.org" , "linux-acpi@vger.kernel.org" , Linus Walleij , Alexandre Courbot , "Rafael J. Wysocki" , Len Brown , "sakari.ailus@linux.intel.com" Subject: Re: [PATCH v4 1/3] mfd: Add new mfd device TPS68470 Message-ID: <20170726082304.7j4lbvsuyyu7owqy@dell> References: <1500506426-3047-1-git-send-email-rajmohan.mani@intel.com> <1500506426-3047-2-git-send-email-rajmohan.mani@intel.com> <20170720090300.ayx5pz5l4yntefpt@dell> <6F87890CF0F5204F892DEA1EF0D77A59725DD60A@FMSMSX114.amr.corp.intel.com> <20170725091012.3hpxihekht2j35xb@dell> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1324 Lines: 46 On Tue, 25 Jul 2017, Andy Shevchenko wrote: > On Tue, Jul 25, 2017 at 12:10 PM, Lee Jones wrote: > > On Fri, 21 Jul 2017, Mani, Rajmohan wrote: > >> > On Wed, 19 Jul 2017, Rajmohan Mani wrote: > > >> > > + /* Force software reset */ > >> > > + ret = regmap_write(regmap, TPS68470_REG_RESET, > >> > TPS68470_REG_RESET_MASK); > >> > > + if (ret < 0) > >> > > >> > Will 'if (!ret)' do? > >> > > >> > >> We intend to check error conditions and bail out. So, if (ret < 0) works for this. > > > > Yes, 'if (!ret)' does that too. > > Did you mean > > if (ret) > return ret; > > ? Yes, I just noticed! Apologies for the confusion. > I briefly checked few ->read() and ->write() implementations and > didn't find any evidence of positive numbers that can be returned. > Documentation (kernel doc) doesn't shed a light on that. So, to me it > sounds unspecified. > > So, for now (until documentation will be fixed) I would rely on > if (ret < 0) It's not unspecified. The regmap methods call into regcache_write(), where the kerneldoc is clear. Perhaps we can also change the regmap kerneldoc headers too to match, which might lessen the disparity. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog