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 97079C636CB for ; Sat, 17 Jul 2021 16:42:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A5CD6115A for ; Sat, 17 Jul 2021 16:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231874AbhGQQpM (ORCPT ); Sat, 17 Jul 2021 12:45:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:59764 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231346AbhGQQpL (ORCPT ); Sat, 17 Jul 2021 12:45:11 -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 18D1E61159; Sat, 17 Jul 2021 16:42:08 +0000 (UTC) Date: Sat, 17 Jul 2021 17:44:32 +0100 From: Jonathan Cameron To: Hui Liu Cc: , , , , , , , , , , , , , , , Subject: Re: [PATCH] iio: mtk-auxadc: add mutex_destroy Message-ID: <20210717174432.7e69e4e9@jic23-huawei> In-Reply-To: <20210715093523.29844-2-hui.liu@mediatek.com> References: <20210715093523.29844-1-hui.liu@mediatek.com> <20210715093523.29844-2-hui.liu@mediatek.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, 15 Jul 2021 17:35:23 +0800 Hui Liu wrote: > Add mutex_destroy when probe fail and remove device. > > Signed-off-by: Hui Liu Hi Hui Liu, We very very rarely bother to call mutex_destroy(). The reason is that it is only a non noop in when mutex debugging is enabled and that is only useful if there is a plausible route in which it could be used after the mutex_destroy. Given these are both at the ends of removal paths, I don't think this is useful. That's why you will rarely find mutex_destroy() being called. Thanks, Jonathan > --- > drivers/iio/adc/mt6577_auxadc.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c > index 79c1dd68b909..d57243037ad6 100644 > --- a/drivers/iio/adc/mt6577_auxadc.c > +++ b/drivers/iio/adc/mt6577_auxadc.c > @@ -289,6 +289,7 @@ static int mt6577_auxadc_probe(struct platform_device *pdev) > ret = iio_device_register(indio_dev); > if (ret < 0) { > dev_err(&pdev->dev, "failed to register iio device\n"); > + mutex_destroy(&adc_dev->lock); > goto err_power_off; > } > > @@ -313,6 +314,7 @@ static int mt6577_auxadc_remove(struct platform_device *pdev) > 0, MT6577_AUXADC_PDN_EN); > > clk_disable_unprepare(adc_dev->adc_clk); > + mutex_destroy(&adc_dev->lock); > > return 0; > }