Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1751775AbdC1Lxl (ORCPT <rfc822;w@1wt.eu>);
        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
        <rfc822;linux-kernel@vger.kernel.org>);
        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 <ckeepax@opensource.wolfsonmicro.com>
To: Daniel Baluta <daniel.baluta@gmail.com>
CC: Daniel Baluta <daniel.baluta@nxp.com>,
        Nicolin Chen <nicoleotsuka@gmail.com>, Mark Brown <broonie@kernel.org>,
        <alsa-devel@alsa-project.org>, Timur Tabi <timur@tabi.org>,
        <Xiubo.Lee@gmail.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Liam Girdwood <lgirdwood@gmail.com>, Takashi Iwai <tiwai@suse.com>,
        <fabio.estevam@nxp.com>, <linuxppc-dev@lists.ozlabs.org>
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>
 <CAEnQRZAx1o9xtbf3u1A_Zun7MSaJjdjunpJm1Q6=ZAA3beoFbA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <CAEnQRZAx1o9xtbf3u1A_Zun7MSaJjdjunpJm1Q6=ZAA3beoFbA@mail.gmail.com>
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: <linux-kernel.vger.kernel.org>
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
> <ckeepax@opensource.wolfsonmicro.com> 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