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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 42D6AC47094 for ; Mon, 31 May 2021 08:57:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 25E6261249 for ; Mon, 31 May 2021 08:57:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230499AbhEaI7S (ORCPT ); Mon, 31 May 2021 04:59:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:47288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231148AbhEaI7R (ORCPT ); Mon, 31 May 2021 04:59:17 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BEA5160FDA; Mon, 31 May 2021 08:57:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622451458; bh=S4X7tjaYcmG+zC4vTgFFWerXX/yrMd1EXDBKdDLGVGs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NMRcfzNTf5DJGgFY0NSMAIiYMFXcMYDaaT697DypVI0j9Hxccv4uEY8ac/xGzz+Qe 4Mis69v7uQT9bbwNRONLbe4L+EHFObCfMPKoskePUeOJUNfAOCZLXqUYrrHq7BCSCV k+vgOLaaO9Uex42Y8t5GHG56ckGcRq4n8XYX4AFiL8qP7CFvpbycXG8kKMcbcDVlG/ 7Vym5LmsBxTby8imdj4THUJLALlrzWXXV4igJmYA8sFQu9WEVf+rrZvxg1mbyJSVqN ptlH5enhQUmghFUzum8tokhSMbp7ZQmI/hitv4cjZ/EwF+Lk2aY4dge8a3KbtxPS7C LElmlJPcoyTpg== Date: Mon, 31 May 2021 14:27:34 +0530 From: Vinod Koul To: "yukuai (C)" Cc: mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, michal.simek@xilinx.com, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, yi.zhang@huawei.com Subject: Re: [PATCH 2/3] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe() Message-ID: References: <20210517081826.1564698-1-yukuai3@huawei.com> <20210517081826.1564698-3-yukuai3@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 31-05-21, 14:11, yukuai (C) wrote: > On 2021/05/31 12:00, Vinod Koul wrote: > > On 17-05-21, 16:18, Yu Kuai wrote: > > > pm_runtime_get_sync will increment pm usage counter even it failed. > > > Forgetting to putting operation will result in reference leak here. > > > Fix it by replacing it with pm_runtime_resume_and_get to keep usage > > > counter balanced. > > > > > > Reported-by: Hulk Robot > > > Signed-off-by: Yu Kuai > > > --- > > > drivers/dma/sh/usb-dmac.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c > > > index 8f7ceb698226..2a6c8fd8854e 100644 > > > --- a/drivers/dma/sh/usb-dmac.c > > > +++ b/drivers/dma/sh/usb-dmac.c > > > @@ -796,7 +796,7 @@ static int usb_dmac_probe(struct platform_device *pdev) > > > /* Enable runtime PM and initialize the device. */ > > > pm_runtime_enable(&pdev->dev); > > > - ret = pm_runtime_get_sync(&pdev->dev); > > > + ret = pm_runtime_resume_and_get(&pdev->dev); > > > > This does not seem to fix anything.. the below goto goes and disables > > the runtime_pm for this device and thus there wont be any leak > Hi, > > If pm_runtime_get_sync() fails and increments the pm.usage_count > variable, pm_runtime_disable() does not reset the counter, and > we still need to decrement the usage count when pm_runtime_get_sync() > fails. Do I miss anthing? Yes the rumtime_pm is disabled on failure here and the count would have no consequence... -- ~Vinod