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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5F46C433FE for ; Mon, 21 Mar 2022 21:12:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230005AbiCUVOP (ORCPT ); Mon, 21 Mar 2022 17:14:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229496AbiCUVON (ORCPT ); Mon, 21 Mar 2022 17:14:13 -0400 Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9A20249C4D; Mon, 21 Mar 2022 14:12:45 -0700 (PDT) Received: by mail-pf1-x434.google.com with SMTP id g19so16541453pfc.9; Mon, 21 Mar 2022 14:12:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=1iwp5l85v8loGCVgV3W8r/7bIeP1JnAKj67uJsPecXk=; b=Eomn0Jx5RUxC+YScVnk3ZoRStMrY2lBLbthcHauzI8h2o4BUm+AW0p/8QJGxj8H8r6 NDr9VdOuu0KUa3rV8hzGHAz/M5W/vHS+sYOy6CqsqvP1z0kty0WTSuOpWY9cWlQMIzZW cF3Q+p3I3AVwwML2KnWiUJV8HXlKHPIBqfYGjlsLxbaTiHtPOmCdszhJoHb/PQ9vRfDI tQNfTxYaZcDtFoR32W1fYIULCfd3sNCfq4GYZqL/MS/k+jgnjA23BQNP6a3rPZ0wIqT+ 9+ljw7njaXSAzzp6eAnM814PHOPiBc6AG6Ad+ijquFrBY/8AH65bLqXIcm2tX0CWKdY9 Hrzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=1iwp5l85v8loGCVgV3W8r/7bIeP1JnAKj67uJsPecXk=; b=HN15i9a3wLknAlF4+sFMmIvVxxpAeDsM0UYLsIw0OrAWORtSLEmPOyvYYKhIa11cY+ BGcVMoXUSgrPRnClLaUyFX6nMGVC0z/2nFQNFaF2HxHAzekjFzKYtKxyNwGwzX7Doob8 dbd8Kc2KR0Oqv4ZCqA5ipJ/16GTGuH02kybrpfUXvuXeASl1DnEXrBHhILP/R7eui2u8 HS0nJp+pwelV4vqnDYETfMXu6W2IKjSNzcLoj3gcw8IRUL6BHeMXgWXCrPFykWGgWnOP C/7XyKcwNE2+dPntpUofJZBUrClW/E42JNiCLq0FrhYwVXSxNwRDjlSBI1f7bIml8TEp Prmw== X-Gm-Message-State: AOAM531cuQpTZBZl/B41f7gelunH7p/d41Z5PaP5dF4yiDAu8wH7NtuR nCquvflCRt4hjTlE+ojsvwk= X-Google-Smtp-Source: ABdhPJzWbVEduY71wUeDaKyxRoH0iYM4Njyu/u6RqfKYFjSAwMsModi746XVxVEvL2LgbTpKJl1ssQ== X-Received: by 2002:a63:4919:0:b0:382:6f3d:e48 with SMTP id w25-20020a634919000000b003826f3d0e48mr7252770pga.613.1647897165090; Mon, 21 Mar 2022 14:12:45 -0700 (PDT) Received: from jagath-PC ([115.99.184.169]) by smtp.gmail.com with ESMTPSA id k14-20020a056a00134e00b004f83f05608esm21052510pfu.31.2022.03.21.14.12.43 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 21 Mar 2022 14:12:44 -0700 (PDT) Date: Tue, 22 Mar 2022 02:42:41 +0530 From: Jagath Jog J To: Jonathan Cameron Cc: dan@dlrobertson.com, andy.shevchenko@gmail.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 1/5] iio: accel: bma400: conversion to device-managed function Message-ID: <20220321211237.GA10058@jagath-PC> References: <20220319181023.8090-1-jagathjog1996@gmail.com> <20220319181023.8090-2-jagathjog1996@gmail.com> <20220320171422.614a4f25@jic23-huawei> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220320171422.614a4f25@jic23-huawei> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Mar 20, 2022 at 05:14:22PM +0000, Jonathan Cameron wrote: > On Sat, 19 Mar 2022 23:40:19 +0530 > Jagath Jog J wrote: > > > This is a conversion to device-managed by using devm_iio_device_register > > inside probe function, now disabling the regulator and putting bma400 to > > power down via a devm_add_action_or_reset() hook. > > > > The dev_set_drvdata() call, bma400_remove() function and hooks in the I2C > > and SPI driver struct is removed as devm_iio_device_register function is > > used to automatically unregister on driver detach. > > > > Signed-off-by: Jagath Jog J > > Hi Jagath, > > There is an oddity in the existing driver that has lead this in > what I think is the wrong direction. See below. > > > --- > > drivers/iio/accel/bma400.h | 2 -- > > drivers/iio/accel/bma400_core.c | 39 ++++++++++++++------------------- > > drivers/iio/accel/bma400_i2c.c | 8 ------- > > drivers/iio/accel/bma400_spi.c | 8 ------- > > 4 files changed, 17 insertions(+), 40 deletions(-) > > > > diff --git a/drivers/iio/accel/bma400.h b/drivers/iio/accel/bma400.h > > index c4c8d74155c2..e938da5a57b4 100644 > > --- a/drivers/iio/accel/bma400.h > > +++ b/drivers/iio/accel/bma400.h > > @@ -94,6 +94,4 @@ extern const struct regmap_config bma400_regmap_config; > > > > int bma400_probe(struct device *dev, struct regmap *regmap, const char *name); > > > > -void bma400_remove(struct device *dev); > > - > > #endif > > diff --git a/drivers/iio/accel/bma400_core.c b/drivers/iio/accel/bma400_core.c > > index fd2647b728d3..dcc7549c7a0e 100644 > > --- a/drivers/iio/accel/bma400_core.c > > +++ b/drivers/iio/accel/bma400_core.c > > @@ -793,6 +793,19 @@ static const struct iio_info bma400_info = { > > .write_raw_get_fmt = bma400_write_raw_get_fmt, > > }; > > > > +static void bma400_disable(void *data_ptr) > > +{ > > + struct bma400_data *data = data_ptr; > > + int ret; > > + > > + ret = bma400_set_power_mode(data, POWER_MODE_SLEEP); > > + if (ret) > > + dev_warn(data->dev, "Failed to put device into sleep mode (%pe)\n", > > + ERR_PTR(ret)); > > + > > + regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators); > > So this raised alarm bells. You almost never want a devm callback to do two things. > > The reason it 'looks' like this might be ok is that the driver is currently calling > bma400_set_power_mode(data, POWER_MODE_SLEEP) in error paths during probe. > I think it should be. If you make that modification first you'll see that to > keep a clean: "only undo things you have done" approach you'll then need > to have a pair of devm_add_action_or_reset() callbacks so as to cover the > disabling of the regulators when the power enabling fails and then to > cover the change to sleep mode if anything else fails. Sure I will add separate functions for regulators disable and power disable then use them with help of two devm_add_action_or_reset() callbacks in bma400_init function. Is below is correct? static void bma400_regulators_disable(void *data_ptr) { struct bma400_data *data = data_ptr; regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators); } static void bma400_power_disable(void *data_ptr) { struct bma400_data *data = data_ptr; int ret; mutex_lock(&data->mutex); ret = bma400_set_power_mode(data, POWER_MODE_SLEEP); if (ret) dev_warn(data->dev, "Failed to put device into sleep mode (%pe)\n", ERR_PTR(ret)); mutex_unlock(&data->mutex); } static int bma400_init(struct bma400_data *data) { unsigned int val; int ret; ...... ret = regulator_bulk_enable(ARRAY_SIZE(data->regulators), data->regulators); if (ret) { dev_err(data->dev, "Failed to enable regulators: %d\n", ret); goto out; } ret = devm_add_action_or_reset(data->dev, bma400_regulators_disable, data); if (ret) return ret; ... if (data->power_mode != POWER_MODE_NORMAL) { ret = bma400_set_power_mode(data, POWER_MODE_NORMAL); if (ret) { dev_err(data->dev, "Failed to wake up the device\n"); goto err_reg_disable; } /* * TODO: The datasheet waits 1500us here in the example, but * lists 2/ODR as the wakeup time. */ usleep_range(1500, 2000); } ret = devm_add_action_or_reset(data->dev, bma400_power_disable, data); if (ret) return ret; .... return regmap_write(data->regmap, BMA400_ACC_CONFIG2_REG, 0x00); err_reg_disable: regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators); out: return ret; } > > > Jonathan > > > +} > > + > > int bma400_probe(struct device *dev, struct regmap *regmap, const char *name) > > { > > struct iio_dev *indio_dev; > > @@ -822,31 +835,13 @@ int bma400_probe(struct device *dev, struct regmap *regmap, const char *name) > > indio_dev->num_channels = ARRAY_SIZE(bma400_channels); > > indio_dev->modes = INDIO_DIRECT_MODE; > > > > - dev_set_drvdata(dev, indio_dev); > > - > > - return iio_device_register(indio_dev); > > -} > > -EXPORT_SYMBOL(bma400_probe); > > - > > -void bma400_remove(struct device *dev) > > -{ > > - struct iio_dev *indio_dev = dev_get_drvdata(dev); > > - struct bma400_data *data = iio_priv(indio_dev); > > - int ret; > > - > > - mutex_lock(&data->mutex); > > - ret = bma400_set_power_mode(data, POWER_MODE_SLEEP); > > - mutex_unlock(&data->mutex); > > - > > + ret = devm_add_action_or_reset(dev, bma400_disable, data); > > if (ret) > > - dev_warn(dev, "Failed to put device into sleep mode (%pe)\n", ERR_PTR(ret)); > > - > > - regulator_bulk_disable(ARRAY_SIZE(data->regulators), > > - data->regulators); > > + return ret; > > > > - iio_device_unregister(indio_dev); > > + return devm_iio_device_register(dev, indio_dev); > > } > > -EXPORT_SYMBOL(bma400_remove); > > +EXPORT_SYMBOL(bma400_probe); > > > > MODULE_AUTHOR("Dan Robertson "); > > MODULE_DESCRIPTION("Bosch BMA400 triaxial acceleration sensor core"); > > diff --git a/drivers/iio/accel/bma400_i2c.c b/drivers/iio/accel/bma400_i2c.c > > index f50df5310beb..56da06537562 100644 > > --- a/drivers/iio/accel/bma400_i2c.c > > +++ b/drivers/iio/accel/bma400_i2c.c > > @@ -27,13 +27,6 @@ static int bma400_i2c_probe(struct i2c_client *client, > > return bma400_probe(&client->dev, regmap, id->name); > > } > > > > -static int bma400_i2c_remove(struct i2c_client *client) > > -{ > > - bma400_remove(&client->dev); > > - > > - return 0; > > -} > > - > > static const struct i2c_device_id bma400_i2c_ids[] = { > > { "bma400", 0 }, > > { } > > @@ -52,7 +45,6 @@ static struct i2c_driver bma400_i2c_driver = { > > .of_match_table = bma400_of_i2c_match, > > }, > > .probe = bma400_i2c_probe, > > - .remove = bma400_i2c_remove, > > .id_table = bma400_i2c_ids, > > }; > > > > diff --git a/drivers/iio/accel/bma400_spi.c b/drivers/iio/accel/bma400_spi.c > > index 9f622e37477b..96dc9c215401 100644 > > --- a/drivers/iio/accel/bma400_spi.c > > +++ b/drivers/iio/accel/bma400_spi.c > > @@ -87,13 +87,6 @@ static int bma400_spi_probe(struct spi_device *spi) > > return bma400_probe(&spi->dev, regmap, id->name); > > } > > > > -static int bma400_spi_remove(struct spi_device *spi) > > -{ > > - bma400_remove(&spi->dev); > > - > > - return 0; > > -} > > - > > static const struct spi_device_id bma400_spi_ids[] = { > > { "bma400", 0 }, > > { } > > @@ -112,7 +105,6 @@ static struct spi_driver bma400_spi_driver = { > > .of_match_table = bma400_of_spi_match, > > }, > > .probe = bma400_spi_probe, > > - .remove = bma400_spi_remove, > > .id_table = bma400_spi_ids, > > }; > > >