Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752017AbcJKEc2 (ORCPT <rfc822;w@1wt.eu>);
        Tue, 11 Oct 2016 00:32:28 -0400
Received: from mga01.intel.com ([192.55.52.88]:34744 "EHLO mga01.intel.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1751123AbcJKEc0 (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 11 Oct 2016 00:32:26 -0400
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.31,476,1473145200"; 
   d="scan'208";a="1068766794"
Subject: Re: [PATCH v17 3/4] usb: gadget: Integrate with the usb gadget
 supporting for usb charger
To: Baolin Wang <baolin.wang@linaro.org>
References: <cover.1476000169.git.baolin.wang@linaro.org>
 <700f8d4fc3c52418eeba5445f6822093cc9ff036.1476000169.git.baolin.wang@linaro.org>
 <57FC573C.2060301@linux.intel.com>
 <CAMz4kuL5yk5EZQ37ofA39uK_JwYYH5DA_=Z+nLEMO06KvyQmDQ@mail.gmail.com>
Cc: Felipe Balbi <balbi@kernel.org>, Greg KH <gregkh@linuxfoundation.org>,
        Sebastian Reichel <sre@kernel.org>,
        Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>,
        David Woodhouse <dwmw2@infradead.org>, robh@kernel.org,
        Jun Li <jun.li@nxp.com>, Marek Szyprowski <m.szyprowski@samsung.com>,
        Ruslan Bilovol <ruslan.bilovol@gmail.com>,
        Peter Chen <peter.chen@freescale.com>,
        Alan Stern <stern@rowland.harvard.edu>, r.baldyga@samsung.com,
        grygorii.strashko@ti.com,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
        Lee Jones <lee.jones@linaro.org>, Mark Brown <broonie@kernel.org>,
        John Stultz <john.stultz@linaro.org>,
        Charles Keepax <ckeepax@opensource.wolfsonmicro.com>,
        patches@opensource.wolfsonmicro.com,
        Linux PM list <linux-pm@vger.kernel.org>,
        USB <linux-usb@vger.kernel.org>,
        device-mainlining@lists.linuxfoundation.org,
        LKML <linux-kernel@vger.kernel.org>
From: Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <57FC6B51.9030205@linux.intel.com>
Date: Tue, 11 Oct 2016 12:32:17 +0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.5.1
MIME-Version: 1.0
In-Reply-To: <CAMz4kuL5yk5EZQ37ofA39uK_JwYYH5DA_=Z+nLEMO06KvyQmDQ@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1100
Lines: 33

Hi,

On 10/11/2016 12:07 PM, Baolin Wang wrote:
>>>  /*
>>> >> + * usb_charger_unregister() - Unregister a usb charger.
>>> >> + * @uchger - the usb charger to be unregistered.
>>> >> + */
>>> >> +static int usb_charger_unregister(struct usb_charger *uchger)
>>> >> +{
>>> >> +     ida_simple_remove(&usb_charger_ida, uchger->id);
>>> >> +     sysfs_remove_groups(&uchger->gadget->dev.kobj, usb_charger_groups);
>>> >> +
>>> >> +     mutex_lock(&charger_lock);
>>> >> +     list_del(&uchger->list);
>>> >> +     mutex_unlock(&charger_lock);
>>> >> +
>>> >> +     kfree(uchger);
>> >
>> > Any reasons you want to put kfree() here? You allocated the memory
>> > in usb_charger_init(). Isn't usb_charger_exit() a better place?
> The usb_charger_exit() will issue usb_charger_unregister() and we need
> use the usb_charger structure in usb_charger_unregister() to
> unregister the usb charger.
>

This seems not to be a strong reason. :-)

You can unregister the charger first and then free the structure.
Just do the reverse operation of what you have done in the init
function.

Best regards,
Lu Baolu