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,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 3113EC636CB for ; Sat, 17 Jul 2021 18:17:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1673061154 for ; Sat, 17 Jul 2021 18:17:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234759AbhGQSUG (ORCPT ); Sat, 17 Jul 2021 14:20:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:35628 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233441AbhGQSUF (ORCPT ); Sat, 17 Jul 2021 14:20:05 -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 60EE761153; Sat, 17 Jul 2021 18:17:07 +0000 (UTC) Date: Sat, 17 Jul 2021 19:19:30 +0100 From: Jonathan Cameron To: Alexandru Ardelean Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, pmeerw@pmeerw.net Subject: Re: [PATCH 2/2] iio: temperature: tmp006: make sure the chip is powered up in probe Message-ID: <20210717191930.256a2cca@jic23-huawei> In-Reply-To: <20210624081924.15897-2-aardelean@deviqon.com> References: <20210624081924.15897-1-aardelean@deviqon.com> <20210624081924.15897-2-aardelean@deviqon.com> X-Mailer: Claws Mail 3.18.0 (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, 24 Jun 2021 11:19:24 +0300 Alexandru Ardelean wrote: > When the device is probed, there's no guarantee that the device is not in > power-down mode. This can happen if the driver is unregistered and > re-probed. > > To make sure this doesn't happen, the value of the TMP006_CONFIG register > (which is read in the probe function and stored in the device's private > data) is being checked to see if the MOD bits have the correct value. > > This is a fix for a somewhat-rare corner case. As it stands, this doesn't > look like a high priority to go into the Fixes route. > > Signed-off-by: Alexandru Ardelean This one 'looks' right and as it's been on the list a while I'll apply it. Would be great if anyone can test it though! Series applied. Thanks, Jonathan > --- > drivers/iio/temperature/tmp006.c | 33 +++++++++++++++++++++----------- > 1 file changed, 22 insertions(+), 11 deletions(-) > > diff --git a/drivers/iio/temperature/tmp006.c b/drivers/iio/temperature/tmp006.c > index db1ac6029c27..e4943a0bc9aa 100644 > --- a/drivers/iio/temperature/tmp006.c > +++ b/drivers/iio/temperature/tmp006.c > @@ -193,15 +193,23 @@ static bool tmp006_check_identification(struct i2c_client *client) > return mid == TMP006_MANUFACTURER_MAGIC && did == TMP006_DEVICE_MAGIC; > } > > -static int tmp006_powerdown(struct tmp006_data *data) > +static int tmp006_power(struct device *dev, bool up) > { > + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); > + struct tmp006_data *data = iio_priv(indio_dev); > + > + if (up) > + data->config |= TMP006_CONFIG_MOD_MASK; > + else > + data->config &= ~TMP006_CONFIG_MOD_MASK; > + > return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG, > - data->config & ~TMP006_CONFIG_MOD_MASK); > + data->config); > } > > -static void tmp006_powerdown_cleanup(void *data) > +static void tmp006_powerdown_cleanup(void *dev) > { > - tmp006_powerdown(data); > + tmp006_power(dev, false); > } > > static int tmp006_probe(struct i2c_client *client, > @@ -239,7 +247,14 @@ static int tmp006_probe(struct i2c_client *client, > return ret; > data->config = ret; > > - ret = devm_add_action(&client->dev, tmp006_powerdown_cleanup, data); > + if ((ret & TMP006_CONFIG_MOD_MASK) != TMP006_CONFIG_MOD_MASK) { > + ret = tmp006_power(&client->dev, true); > + if (ret < 0) > + return ret; > + } > + > + ret = devm_add_action_or_reset(&client->dev, tmp006_powerdown_cleanup, > + &client->dev); > if (ret < 0) > return ret; > > @@ -249,16 +264,12 @@ static int tmp006_probe(struct i2c_client *client, > #ifdef CONFIG_PM_SLEEP > static int tmp006_suspend(struct device *dev) > { > - struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev)); > - return tmp006_powerdown(iio_priv(indio_dev)); > + return tmp006_power(dev, false); > } > > static int tmp006_resume(struct device *dev) > { > - struct tmp006_data *data = iio_priv(i2c_get_clientdata( > - to_i2c_client(dev))); > - return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG, > - data->config | TMP006_CONFIG_MOD_MASK); > + return tmp006_power(dev, true); > } > #endif >