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=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 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 49172C433B4 for ; Thu, 13 May 2021 15:37:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 217156142C for ; Thu, 13 May 2021 15:37:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234977AbhEMPjD (ORCPT ); Thu, 13 May 2021 11:39:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:42776 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234960AbhEMPix (ORCPT ); Thu, 13 May 2021 11:38:53 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2896561439; Thu, 13 May 2021 15:37:41 +0000 (UTC) Date: Thu, 13 May 2021 16:38:50 +0100 From: Jonathan Cameron To: Alexandru Ardelean Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, Jonathan.Cameron@huawei.com, alexandru.tachici@analog.com, linux@deviqon.com Subject: Re: [PATCH v4 04/12] iio: adc: ad7192: handle regulator voltage error first Message-ID: <20210513163850.434d8994@jic23-huawei> In-Reply-To: <20210513120752.90074-5-aardelean@deviqon.com> References: <20210513120752.90074-1-aardelean@deviqon.com> <20210513120752.90074-5-aardelean@deviqon.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 13 May 2021 15:07:44 +0300 Alexandru Ardelean wrote: > This change fixes a corner-case, where for a zero regulator value, the > driver would exit early, initializing the driver only partially. > The driver would be in an unknown state. > > This change reworks the code to check regulator_voltage() return value > for negative (error) first, and return early. This is the more common > idiom. > > Also, this change is removing the 'voltage_uv' variable and using the 'ret' > value directly. The only place where 'voltage_uv' is being used is to > compute the internal reference voltage, and the type of this variable is > 'int' (same are for 'ret'). Using only 'ret' avoids having to assign it on > the error path. > > Fixes: ab0afa65bbc7 ("staging: iio: adc: ad7192: fail probe on get_voltage") > Cc: Alexandru Tachici > Signed-off-by: Alexandru Ardelean I've applied the first 4 patches to the fixes-togreg branch of iio.git and cc'd stable. Added note to the first 3 about the sign-off chain as its a bit unusual for it to include loops ;) I always debate if I should sign-off again when this happens, but decide against. Jonathan > --- > drivers/iio/adc/ad7192.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c > index d3be67aa0522..1141cc13a124 100644 > --- a/drivers/iio/adc/ad7192.c > +++ b/drivers/iio/adc/ad7192.c > @@ -912,7 +912,7 @@ static int ad7192_probe(struct spi_device *spi) > { > struct ad7192_state *st; > struct iio_dev *indio_dev; > - int ret, voltage_uv = 0; > + int ret; > > if (!spi->irq) { > dev_err(&spi->dev, "no IRQ?\n"); > @@ -949,15 +949,12 @@ static int ad7192_probe(struct spi_device *spi) > goto error_disable_avdd; > } > > - voltage_uv = regulator_get_voltage(st->avdd); > - > - if (voltage_uv > 0) { > - st->int_vref_mv = voltage_uv / 1000; > - } else { > - ret = voltage_uv; > + ret = regulator_get_voltage(st->avdd); > + if (ret < 0) { > dev_err(&spi->dev, "Device tree error, reference voltage undefined\n"); > goto error_disable_avdd; > } > + st->int_vref_mv = ret / 1000; > > spi_set_drvdata(spi, indio_dev); > st->chip_info = of_device_get_match_data(&spi->dev);