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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 E634DC433E1 for ; Sat, 16 May 2020 15:35:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C47C120756 for ; Sat, 16 May 2020 15:35:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589643327; bh=6bIdM83OAz8NTK5LfuYkYjYz/+gMNTHlGbMRn7g3eRA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=cyYsS/PAQfaeoC4kKpY7tjomNSgSxnqpYwoQsdwFNRiWE+B8k76L8sSO+2ye/UTP+ eHDMFBQAphEp+RUWZd4lXkSRU184YwInmMCnTXT31mZzvTIInj18Sisbz4GzaKJ3U/ T4oKSOuw5LeyKIDWtw6DXm9X37cUVVYoCqmibnrU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726995AbgEPPf1 (ORCPT ); Sat, 16 May 2020 11:35:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:36920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726663AbgEPPf0 (ORCPT ); Sat, 16 May 2020 11:35:26 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) (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 3DE4720727; Sat, 16 May 2020 15:35:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589643326; bh=6bIdM83OAz8NTK5LfuYkYjYz/+gMNTHlGbMRn7g3eRA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=b4273gexRENjUClnSjPWBqppBfsxCPCulwXSSMnKmtQkW2MzB/1hej7sgTuuHA8M4 CmO7PmyAlU/3gX5mX2zuFSuVCQ6W0S4XZnhrLtaL0TAmHvKPfY8ew93CtkLKczWPRC xHYCcily2ddVLnRI0BJ88lzvL1gYXZ9Q3vp1ttjE= Date: Sat, 16 May 2020 16:35:21 +0100 From: Jonathan Cameron To: Sergiu Cuciurean Cc: , , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Maxime Coquelin , Alexandre Torgue , Fabrice Gasnier , , Subject: Re: [PATCH] iio: stm32-dac: Replace indio_dev->mlock with own device lock Message-ID: <20200516163521.2812cf86@archlinux> In-Reply-To: <20200514085018.79948-1-sergiu.cuciurean@analog.com> References: <20200514085018.79948-1-sergiu.cuciurean@analog.com> X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 14 May 2020 11:50:12 +0300 Sergiu Cuciurean wrote: > As part of the general cleanup of indio_dev->mlock, this change replaces > it with a local lock on the device's state structure. > > Signed-off-by: Sergiu Cuciurean > --- > drivers/iio/dac/stm32-dac.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/iio/dac/stm32-dac.c b/drivers/iio/dac/stm32-dac.c > index f22c1d9129b2..74b9474c8590 100644 > --- a/drivers/iio/dac/stm32-dac.c > +++ b/drivers/iio/dac/stm32-dac.c > @@ -26,9 +26,11 @@ > /** > * struct stm32_dac - private data of DAC driver > * @common: reference to DAC common data > + * @lock: lock to protect the data buffer during regmap ops In this particular case I'm not sure that's what mlock was being used for. I think it's about avoiding races around checking if powered down and actually doing it. > */ > struct stm32_dac { > struct stm32_dac_common *common; > + struct mutex lock; > }; > > static int stm32_dac_is_enabled(struct iio_dev *indio_dev, int channel) > @@ -58,10 +60,10 @@ static int stm32_dac_set_enable_state(struct iio_dev *indio_dev, int ch, > int ret; > > /* already enabled / disabled ? */ > - mutex_lock(&indio_dev->mlock); > + mutex_lock(&dac->lock); > ret = stm32_dac_is_enabled(indio_dev, ch); > if (ret < 0 || enable == !!ret) { > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&dac->lock); > return ret < 0 ? ret : 0; > } > > @@ -69,13 +71,13 @@ static int stm32_dac_set_enable_state(struct iio_dev *indio_dev, int ch, > ret = pm_runtime_get_sync(dev); > if (ret < 0) { > pm_runtime_put_noidle(dev); > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&dac->lock); > return ret; > } > } > > ret = regmap_update_bits(dac->common->regmap, STM32_DAC_CR, msk, en); > - mutex_unlock(&indio_dev->mlock); > + mutex_unlock(&dac->lock); > if (ret < 0) { > dev_err(&indio_dev->dev, "%s failed\n", en ? > "Enable" : "Disable"); > @@ -328,6 +330,8 @@ static int stm32_dac_probe(struct platform_device *pdev) > indio_dev->info = &stm32_dac_iio_info; > indio_dev->modes = INDIO_DIRECT_MODE; > > + mutex_init(&dac->lock); > + > ret = stm32_dac_chan_of_init(indio_dev); > if (ret < 0) > return ret;