From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (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 5C7241607B0; Wed, 21 Aug 2024 08:49:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724230200; cv=none; b=bHefmoBFn5BNaaLoxezJ5KQ1YE1RlnK0PnJGvEfH51dyZjl38q1k0V53s1Y6i/qkBAXWp6ZqT93Xzu7oR58B+zHtPgR5TI/S87Rpqz6Bf11I54P0igi9qdah8YjbR4R01LlfO8vXLL2mwRRoHbAKiAJLsEV+68i1PcCLkuWWRKU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724230200; c=relaxed/simple; bh=LirYJXZb09EV7XOmz4Iw6ZLeN4E3SQFaNblmlIT1gXo=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=g07/CBsFkr005PhUnlakjoeYB+TLmHdYI/w0DwEbDaXz6EJHZsffshc7eZD8sGqQ1EogEeW9/KNzOtSvNgqDirTg0p84TbVPrL35ogtv/t0WNZuX3EGBllQwAXMAfoi34bQSoI4oDWomZtnK7/uN6BZtAqX+ipjJy1TBAOPvCY8= 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=45.249.212.190 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 [172.19.88.163]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4WpfzX0fBTz20ltp; Wed, 21 Aug 2024 16:45:12 +0800 (CST) Received: from kwepemm600004.china.huawei.com (unknown [7.193.23.242]) by mail.maildlp.com (Postfix) with ESMTPS id 9F796180019; Wed, 21 Aug 2024 16:49:53 +0800 (CST) Received: from [10.67.121.59] (10.67.121.59) by kwepemm600004.china.huawei.com (7.193.23.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Wed, 21 Aug 2024 16:49:53 +0800 Message-ID: <68ed6185-a602-c0fc-721e-b5d68fea83f8@huawei.com> Date: Wed, 21 Aug 2024 16:49:52 +0800 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v3 02/14] thermal: core: Rearrange checks in thermal_bind_cdev_to_trip() To: "Rafael J. Wysocki" , Linux PM CC: LKML , Daniel Lezcano , Lukasz Luba , Zhang Rui References: <2205737.irdbgypaU6@rjwysocki.net> <3324214.44csPzL39Z@rjwysocki.net> From: "lihuisong (C)" In-Reply-To: <3324214.44csPzL39Z@rjwysocki.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600004.china.huawei.com (7.193.23.242) 在 2024/8/19 23:51, Rafael J. Wysocki 写道: > From: Rafael J. Wysocki > > It is not necessary to look up the thermal zone and the cooling device > in the respective global lists to check whether or not they are > registered. It is sufficient to check whether or not their respective > list nodes are empty for this purpose. > > Use the above observation to simplify thermal_bind_cdev_to_trip(). In > addition, eliminate an unnecessary ternary operator from it. > > Moreover, add lockdep_assert_held() for thermal_list_lock to it because > that lock must be held by its callers when it is running. > > No intentional functional impact. > > Signed-off-by: Rafael J. Wysocki > --- > > v1 -> v3: No changes > > --- > drivers/thermal/thermal_core.c | 16 ++++------------ > 1 file changed, 4 insertions(+), 12 deletions(-) > > Index: linux-pm/drivers/thermal/thermal_core.c > =================================================================== > --- linux-pm.orig/drivers/thermal/thermal_core.c > +++ linux-pm/drivers/thermal/thermal_core.c > @@ -781,25 +781,17 @@ int thermal_bind_cdev_to_trip(struct the > { > struct thermal_instance *dev; > struct thermal_instance *pos; > - struct thermal_zone_device *pos1; > - struct thermal_cooling_device *pos2; > bool upper_no_limit; > int result; > > - list_for_each_entry(pos1, &thermal_tz_list, node) { > - if (pos1 == tz) > - break; > - } > - list_for_each_entry(pos2, &thermal_cdev_list, node) { > - if (pos2 == cdev) > - break; > - } > + lockdep_assert_held(&thermal_list_lock); > > - if (tz != pos1 || cdev != pos2) > + if (list_empty(&tz->node) || list_empty(&cdev->node)) The old verification is ensure that tz and cdev already add to thermal_tz_list and thermal_cdev_list，respectively. Namely, tz and cdev are definitely registered and intialized. The check is ok for all untizalized thermal_zone_device and cooling device. But the new verification doesn't seem to do that. > return -EINVAL; > > /* lower default 0, upper default max_state */ > - lower = lower == THERMAL_NO_LIMIT ? 0 : lower; > + if (lower == THERMAL_NO_LIMIT) > + lower = 0; > > if (upper == THERMAL_NO_LIMIT) { > upper = cdev->max_state; > > > > > .