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=-15.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 46A74C47082 for ; Mon, 31 May 2021 06:11:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2855B610A1 for ; Mon, 31 May 2021 06:11:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230150AbhEaGNQ (ORCPT ); Mon, 31 May 2021 02:13:16 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:2479 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230013AbhEaGNO (ORCPT ); Mon, 31 May 2021 02:13:14 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4FtlGY4D2jz67NS; Mon, 31 May 2021 14:08:37 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Mon, 31 May 2021 14:11:23 +0800 Received: from [10.174.179.129] (10.174.179.129) by dggema762-chm.china.huawei.com (10.1.198.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Mon, 31 May 2021 14:11:22 +0800 Subject: Re: [PATCH 2/3] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe() To: Vinod Koul CC: , , , , , , , References: <20210517081826.1564698-1-yukuai3@huawei.com> <20210517081826.1564698-3-yukuai3@huawei.com> From: "yukuai (C)" Message-ID: Date: Mon, 31 May 2021 14:11:22 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.179.129] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggema762-chm.china.huawei.com (10.1.198.204) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? Thansk! Yu Kuai > >> if (ret < 0) { >> dev_err(&pdev->dev, "runtime PM get sync failed (%d)\n", ret); >> goto error_pm; >> -- >> 2.25.4 >