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=-14.6 required=3.0 tests=BAYES_00,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=ham 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 8773DC433E2 for ; Wed, 16 Sep 2020 17:53:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45822206F7 for ; Wed, 16 Sep 2020 17:53:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600278796; bh=qtv1VH/lpDHNP4K1hT8rAdmDRzl6jlj/EIejRq6sqbM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=1lZDiIaWt3qsympaY8+/RKWj52Y/eaz24jPheOAtGVh9a/FQ2eIBe7tZ1c/Au5K1v 9StVrK0gjwm9d+fYHeBEqb+hoqhMtlCAhDhWS36VUKWFAIrSna5udHcmq2s1Urmfcp sVKWg2ixr7PAKdDS4a9bHbYpUDNFgiVgZclV4K0w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727561AbgIPRxF (ORCPT ); Wed, 16 Sep 2020 13:53:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:43374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727294AbgIPRwg (ORCPT ); Wed, 16 Sep 2020 13:52:36 -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 2DA05206F7; Wed, 16 Sep 2020 17:52:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600278755; bh=qtv1VH/lpDHNP4K1hT8rAdmDRzl6jlj/EIejRq6sqbM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=JrVlBOLxNcilm6sLhM9bAJJOwFcJcdsVCk8k8N5S1f2dOztgBjoFniBlVcxNGf07N ikMhBD9w4QtsOnVMbBvdBylxMa6WEdZ6zney8xAm8/+iu+wtHo0f4vHzypodHRsz9Y O8b76NNvKUPPw+pgOy5YlKh+MBvOVrP/lU5aPFnM= Date: Wed, 16 Sep 2020 18:52:30 +0100 From: Jonathan Cameron To: Fabrice Gasnier Cc: Alexandru Ardelean , , , , , , , , Sergiu Cuciurean Subject: Re: [PATCH v2] iio: stm32-dac: Replace indio_dev->mlock with own device lock Message-ID: <20200916185230.45c0b7d4@archlinux> In-Reply-To: References: <20200826063850.47625-1-alexandru.ardelean@analog.com> <20200916092349.75647-1-alexandru.ardelean@analog.com> X-Mailer: Claws Mail 3.17.6 (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-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Wed, 16 Sep 2020 12:18:02 +0200 Fabrice Gasnier wrote: > On 9/16/20 11:23 AM, Alexandru Ardelean wrote: > > From: Sergiu Cuciurean > > > > As part of the general cleanup of indio_dev->mlock, this change replaces > > it with a local lock. The lock protects against potential races when > > reading the CR reg and then updating, so that the state of pm_runtime > > is consistent between the two operations. > > > > This is part of a bigger cleanup. > > Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/ > > > > Signed-off-by: Sergiu Cuciurean > > Signed-off-by: Alexandru Ardelean > > --- > > drivers/iio/dac/stm32-dac.c | 13 +++++++++---- > > 1 file changed, 9 insertions(+), 4 deletions(-) > > Hi Alexandru, > > Many thanks for this updated patch, > > Reviewed-by: Fabrice Gasnier Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to poke at it. Thanks, Jonathan > > Best regards, > Fabrice > > > > > diff --git a/drivers/iio/dac/stm32-dac.c b/drivers/iio/dac/stm32-dac.c > > index 092c796fa3d9..12dec68c16f7 100644 > > --- a/drivers/iio/dac/stm32-dac.c > > +++ b/drivers/iio/dac/stm32-dac.c > > @@ -26,9 +26,12 @@ > > /** > > * struct stm32_dac - private data of DAC driver > > * @common: reference to DAC common data > > + * @lock: lock to protect against potential races when reading > > + * and update CR, to keep it in sync with pm_runtime > > */ > > 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 +61,10 @@ 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 +72,13 @@ 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"); > > @@ -327,6 +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; > >