From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756007AbbJ1Sh6 (ORCPT ); Wed, 28 Oct 2015 14:37:58 -0400 Received: from seldrel01.sonyericsson.com ([37.139.156.2]:6821 "EHLO seldrel01.sonyericsson.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752276AbbJ1Sh4 (ORCPT ); Wed, 28 Oct 2015 14:37:56 -0400 Date: Wed, 28 Oct 2015 11:37:50 -0700 From: Bjorn Andersson To: Joe Perches CC: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Johan Hovold , Peter Meerwald , "linux-iio@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH 2/3] iio: light: lm3533-als: Print error message on invalid resistance Message-ID: <20151028183750.GB24668@usrtlx11787.corpusers.net> References: <1445796586-28683-1-git-send-email-bjorn.andersson@sonymobile.com> <1445796586-28683-2-git-send-email-bjorn.andersson@sonymobile.com> <1445973507.2757.40.camel@perches.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1445973507.2757.40.camel@perches.com> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 27 Oct 12:18 PDT 2015, Joe Perches wrote: > On Sun, 2015-10-25 at 11:09 -0700, Bjorn Andersson wrote: > > Print an error message to indicate that invalid configuration data was > > provided in the platform_data, rather than just aborting initialization. > > Perhaps it'd be nicer to show the 3 values. > I do agree that it would be helpful to hint the developer about the expected range. The problem I see here though is that, in the case of devicetree we've now moved from resistance to a register value. E.g. specifying 500kOhm in dt would make this piece complain about a resistance of 0 being invalid and I would have to read the code and/or datasheet anyways to find the valid range. The reason I did not put this error print in the dt parser was that I did not want to replicate the resistor limits and I figured it would be useful for platform_data users as well. But if this is going to be informative I think I need to move it. So would you be okay with not improving the message? Or would you like me to just move it into the code in patch 1 - and leave the platform_data case as it was (with a silent failure)? > > diff --git a/drivers/iio/light/lm3533-als.c b/drivers/iio/light/lm3533-als.c > [] > > @@ -743,8 +743,10 @@ static int lm3533_als_set_resistor(struct lm3533_als *als, u8 val) > > { > > int ret; > > > > - if (val < LM3533_ALS_RESISTOR_MIN || val > LM3533_ALS_RESISTOR_MAX) > > + if (val < LM3533_ALS_RESISTOR_MIN || val > LM3533_ALS_RESISTOR_MAX) { > > + dev_err(&als->pdev->dev, "invalid resistor value\n"); > > return -EINVAL; > > + }; > > Regards, Bjorn