Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751775AbdC1Lxl (ORCPT ); Tue, 28 Mar 2017 07:53:41 -0400 Received: from mx0a-001ae601.pphosted.com ([67.231.149.25]:33790 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751501AbdC1Lxj (ORCPT ); Tue, 28 Mar 2017 07:53:39 -0400 Authentication-Results: ppops.net; spf=none smtp.mailfrom=ckeepax@opensource.wolfsonmicro.com Date: Tue, 28 Mar 2017 12:53:06 +0100 From: Charles Keepax To: Daniel Baluta CC: Daniel Baluta , Nicolin Chen , Mark Brown , , Timur Tabi , , Linux Kernel Mailing List , Liam Girdwood , Takashi Iwai , , Subject: Re: [alsa-devel] [PATCH v3 2/2] ASoC: imx-wm8962: Fix codec_clk cleanup Message-ID: <20170328115306.GR6986@localhost.localdomain> References: <1490691532-2086-1-git-send-email-daniel.baluta@nxp.com> <1490691532-2086-3-git-send-email-daniel.baluta@nxp.com> <20170328092103.GQ6986@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=8 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1702020001 definitions=main-1703280107 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1417 Lines: 42 On Tue, Mar 28, 2017 at 01:47:04PM +0300, Daniel Baluta wrote: > On Tue, Mar 28, 2017 at 12:21 PM, Charles Keepax > wrote: > > On Tue, Mar 28, 2017 at 11:58:52AM +0300, Daniel Baluta wrote: > >> Resource managed devm_clk_get only works with platform's device dev. > >> > > > > I feel like this could use an explaination of why not using devm > > is the correct fix, rather than just using the platform device > > for the call. Its not obvious to me, that using the platform > > device would be an issue. > > Hi Charles, > > I see where the confusion comes from :) and I thought the explanation > is obvious from the code, see inline comments. > > Would an explanation like the one below, work better? > > " We cannot use devm_clk_get with &codec_dev->dev device because > the kernel uses pdev->dev to free the managed resources, so we will end > up with a leaking codec_clk reference" > > >> @@ -231,7 +231,7 @@ static int imx_wm8962_probe(struct platform_device *pdev) > >> goto fail; > >> } > > pdev->dev from here: > > >> > >> - codec_clk = devm_clk_get(&codec_dev->dev, NULL); > >> + codec_clk = clk_get(&codec_dev->dev, NULL); > > is different from &codec_dev->dev. > I get that they are different, I just don't get why changing from a devm_clk_get to a clk_get is a better fix than changing &codec->dev to &pdev->dev. Thanks, Charles