From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2BA3D19E7F6; Thu, 5 Sep 2024 15:40:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725550806; cv=none; b=l0HULVZ+/Plj/M0mPdlB30hnOzKw/t6TjlEQCzP4QSKgNuPzcjOZ6LvllhIviGH1BOaH4GPegBwWTZHh4eQMipuiaL7bKi8bytWkxW1hnZ3WnJ4K7bY9gfVxDe7/k7dRAGD7HvIDoUjl5dioFGfEyXeO54jef97l173PGOi7QAQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725550806; c=relaxed/simple; bh=EPTiZwhQ37GUa+OpUKm+nEhH6DWaqYgDjs99p9Cje+U=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=qLRtOrqzBEU1NBEPk0s3FhPso4qwnN4CMFat28Xl0nsRNnriljprPVLNVJy09w+B+QsxayiBOhLg6zVUlWWFvlS578hMDvlPzFzphYaMqZ/F3cIOw2syNpiU/t/2DCUyn0i/fw7VYUS/j0kSqD3ZuHSC7cf6QrXGQBtGAo1eVuo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.252]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4X03S511L5zyR9y; Thu, 5 Sep 2024 23:39:01 +0800 (CST) Received: from kwepemd500012.china.huawei.com (unknown [7.221.188.25]) by mail.maildlp.com (Postfix) with ESMTPS id 609C11800CF; Thu, 5 Sep 2024 23:40:00 +0800 (CST) Received: from [10.67.111.176] (10.67.111.176) by kwepemd500012.china.huawei.com (7.221.188.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Thu, 5 Sep 2024 23:39:59 +0800 Message-ID: <0915517c-50ff-4867-9b6d-e55357d0ed0f@huawei.com> Date: Thu, 5 Sep 2024 23:39:58 +0800 Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH -next 19/19] hwmon: (nzxt-smart2) Use devm_hid_hw_start_and_open in nzxt_smart2_hid_probe() To: Guenter Roeck , , , , , , , , , , , , , , , , CC: , , References: <20240904123607.3407364-1-lizetao1@huawei.com> <20240904123607.3407364-20-lizetao1@huawei.com> From: Li Zetao In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggpeml500017.china.huawei.com (7.185.36.243) To kwepemd500012.china.huawei.com (7.221.188.25) Hi, 在 2024/9/4 22:14, Guenter Roeck 写道: > On 9/4/24 05:36, Li Zetao wrote: >> Currently, the nzxt-smart2 module needs to maintain hid resources >> by itself. Consider using devm_hid_hw_start_and_open helper to ensure > > For all patches: > > s/Consider using/Use/ ok > >> that hid resources are consistent with the device life cycle, and release >> hid resources before device is released. At the same time, it can avoid >> the goto-release encoding, drop the out_hw_close and out_hw_stop >> lables, and directly return the error code when an error occurs. >> >> Signed-off-by: Li Zetao >> --- >>   drivers/hwmon/nzxt-smart2.c | 22 +++------------------- >>   1 file changed, 3 insertions(+), 19 deletions(-) >> >> diff --git a/drivers/hwmon/nzxt-smart2.c b/drivers/hwmon/nzxt-smart2.c >> index df6fa72a6b59..b5721a42c0d3 100644 >> --- a/drivers/hwmon/nzxt-smart2.c >> +++ b/drivers/hwmon/nzxt-smart2.c >> @@ -750,14 +750,10 @@ static int nzxt_smart2_hid_probe(struct >> hid_device *hdev, >>       if (ret) >>           return ret; >> -    ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); >> +    ret = devm_hid_hw_start_and_open(hdev, HID_CONNECT_HIDRAW); >>       if (ret) >>           return ret; >> -    ret = hid_hw_open(hdev); >> -    if (ret) >> -        goto out_hw_stop; >> - >>       hid_device_io_start(hdev); >>       init_device(drvdata, UPDATE_INTERVAL_DEFAULT_MS); >> @@ -765,19 +761,10 @@ static int nzxt_smart2_hid_probe(struct >> hid_device *hdev, >>       drvdata->hwmon = >>           hwmon_device_register_with_info(&hdev->dev, "nzxtsmart2", >> drvdata, >>                           &nzxt_smart2_chip_info, NULL); >> -    if (IS_ERR(drvdata->hwmon)) { >> -        ret = PTR_ERR(drvdata->hwmon); >> -        goto out_hw_close; >> -    } >> +    if (IS_ERR(drvdata->hwmon)) >> +        return PTR_ERR(drvdata->hwmon); >>       return 0; > >     return PTR_ERR_OR_ZERO(drvdata->hwmon); > > Also, this can be optimized further. > >     struct device *hwmon;    // and drop from struct drvdata >     ... >     hwmon = devm_hwmon_device_register_with_info(&hdev->dev, > "nzxtsmart2", drvdata, >                              &nzxt_smart2_chip_info, NULL); > >     return PTR_ERR_OR_ZERO(hwmon); > > and drop the remove function entirely. Benjamin mentioned that there are unsafe scenarios in hid_hw_close_and_stop, and it is necessary to ensure that the driver can not use manual kzalloc/kfree. So, to be extra safe, I would delete .remove in v2. > > Thanks, > Guenter > >> - >> -out_hw_close: >> -    hid_hw_close(hdev); >> - >> -out_hw_stop: >> -    hid_hw_stop(hdev); >> -    return ret; >>   } >>   static void nzxt_smart2_hid_remove(struct hid_device *hdev) >> @@ -785,9 +772,6 @@ static void nzxt_smart2_hid_remove(struct >> hid_device *hdev) >>       struct drvdata *drvdata = hid_get_drvdata(hdev); >>       hwmon_device_unregister(drvdata->hwmon); >> - >> -    hid_hw_close(hdev); >> -    hid_hw_stop(hdev); >>   } >>   static const struct hid_device_id nzxt_smart2_hid_id_table[] = { >