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=-6.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 1FCB7C47094 for ; Mon, 7 Jun 2021 10:19:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF6BC610FB for ; Mon, 7 Jun 2021 10:19:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230097AbhFGKVE (ORCPT ); Mon, 7 Jun 2021 06:21:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:43988 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230193AbhFGKVD (ORCPT ); Mon, 7 Jun 2021 06:21:03 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 728CB6108C; Mon, 7 Jun 2021 10:19:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623061153; bh=VTXaUpTsvgBICiL2lKaVnHTXuZH2cZNa6FWeUX+IisE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RVVTU06jgeAsSo/v/fEAlG1xId7qFWDasaTznd2qQ64Uk30/NJbygYrmH4HWiWaou Nx9OEPtvZlVibiqfpvZU8qf2uIp7A/lSu+BaSGZHU0V1ky2KF3nK24EJix6mir/gkm M5OuKTah7QnercdV/DgyniAVxs5A+4BkYGy6BI/CtHTsdlcO9n5EnmH7Z87tsoTMHL QjpmLdSzV4/7F/ruljRn9IflXQA4J6+rfnM8SZwX2UZv5Uj2wd+PVTRAXd8uo8537i chhMxB+tdfdxIMdeh2+gRz7+jrcEIO+A8a6w1d9t7insDVjhZWJJ3HHSJDtS7G9f7Z GR8wQQl1SVUcQ== Date: Mon, 7 Jun 2021 15:49:09 +0530 From: Vinod Koul To: Johan Hovold Cc: "yukuai (C)" , 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 07-06-21, 10:06, Johan Hovold wrote: > On Thu, Jun 03, 2021 at 04:39:08PM +0530, Vinod Koul wrote: > > On 31-05-21, 11:19, Johan Hovold wrote: > > > On Mon, May 31, 2021 at 02:27:34PM +0530, Vinod Koul wrote: > > > > 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. > > > > > Yes the rumtime_pm is disabled on failure here and the count would have > > > > no consequence... > > > > > > You should still balance the PM usage counter as it isn't reset for > > > example when reloading the driver. > > > > Should I driver trust that on load PM usage counter is balanced and not > > to be reset..? > > Not sure what you're asking here. But a driver should never leave the PM > usage counter unbalanced. Thinking about again, yes we should safely assume the counter is balanced when driver loads.. so unloading while balancing sounds better behaviour Thanks -- ~Vinod