From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4A99C43217 for ; Wed, 12 Oct 2022 19:19:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229893AbiJLTTV (ORCPT ); Wed, 12 Oct 2022 15:19:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229727AbiJLTTS (ORCPT ); Wed, 12 Oct 2022 15:19:18 -0400 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDF5D102DFC; Wed, 12 Oct 2022 12:19:08 -0700 (PDT) Received: by mail-pj1-x102a.google.com with SMTP id b15so16132846pje.1; Wed, 12 Oct 2022 12:19:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:in-reply-to:references:cc:to:from :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=6fX48vIWYpjViCZeXxicInI+kxNPFmk1lK5Wh8mOwOE=; b=hkf1+ecZnUs6So29ZrMzVhnpZJIc7YvWAraVgbsVnnRWZEJ6Z1lwp8UxBEsRbTwTwr H8/IPCQ1QX1OA9//RJK3tfbSMEtAo2QVs/qo0jR0I4pI16ALkwNw3OnVptrBI3kxavel zbA8MPtvTI03WPz0Dloz53jm1H8J3TTp4MtiliFW8gND3R/wG/aObAuHxga5ylwt5QNZ gzPWsRnKwQbBuebprJWh4agaVwkZ8Nk7xe1Ue8o6AzppUH6mDNuR6vWZObWwovfPdy88 Dm/TXUNA3Chit+RmBaxbbIoI8s4PUFM0/poMjOlxhLB5P3rTHcLUvwGdtvBeTiMWNTkw cZwA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:references:cc:to:from :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6fX48vIWYpjViCZeXxicInI+kxNPFmk1lK5Wh8mOwOE=; b=CAOjKOYfC70dSAF1YM3GgIaOKSMskyqZWJkQeIKhYhdeI4xOU7YaGaZlkffioMbPGu gzgW/LFkK/DTKjdfQPYTp6FJAFlts5nLBrA/3HZnttfRDHjSwCtrV5E373mjcJ26jsVO /B8y13Kje439A+UQA0iLonJjDZLVE0mHb/1W72RooppY1XPMCmGQ8mWXtWD2FRXE4f5c tWvggCzk3BCUFPR0UP8qlp9iVkfFYNvCFW3ULa0o56Me4at2wR8s5R2VaZOOt8J4ERWv RrsR5g7DU/h4HMKef/omLlaucr5lTSaU9NNU9WYrwn7tDDfnz/QEgI4CvcpVe5VrF63l yDTg== X-Gm-Message-State: ACrzQf3gEXpiPucR04hduv7jrsC9uc4KCESy6t2+NKAmDWzZYc8/KZxc yyGp8np/RrmADsEx8e2ChGA= X-Google-Smtp-Source: AMsMyM6eTdTcJhsmb+6koMRnl4pt5nemqWVsWU6ktVqtB8uM40UucIJ4B8qmiHyNDzjH6U/E/dBS5g== X-Received: by 2002:a17:90b:1bcb:b0:20d:75b8:ee64 with SMTP id oa11-20020a17090b1bcb00b0020d75b8ee64mr6821059pjb.162.1665602347623; Wed, 12 Oct 2022 12:19:07 -0700 (PDT) Received: from [172.30.1.63] ([14.32.163.5]) by smtp.gmail.com with ESMTPSA id z4-20020a170902ccc400b0018003571809sm10692908ple.224.2022.10.12.12.19.05 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 12 Oct 2022 12:19:07 -0700 (PDT) Message-ID: Date: Thu, 13 Oct 2022 04:19:03 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v2] devfreq: governor: Add a private governor_data for governors in devfreq Content-Language: en-US From: Chanwoo Choi To: Kant Fan , myungjoo.ham@samsung.com, kyungmin.park@samsung.com, cw00.choi@samsung.com Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20221010072202.78731-1-kant@allwinnertech.com> <00ed0b46-54db-330e-8ff8-146ff9a09491@gmail.com> In-Reply-To: <00ed0b46-54db-330e-8ff8-146ff9a09491@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22. 10. 13. 04:00, Chanwoo Choi wrote: > Hi, > > I'm sorry for late reply. It looks good to me. > Instead, this patch should contain the 'Fixes' information > with the following commit because the changed code was merged > on the patch[1]. Also, need to send it to stable mailing list. > > [1] ce26c5bb9569d8b826f01b8620fc16d8da6821e9 > PM / devfreq: Add basic governors > > Lastly, I think that need to change the patch title as following: > - PM / devfreq: governor: Add a private governor_data for governor > > > On 22. 10. 10. 16:22, Kant Fan wrote: >> The member void *data in the structure devfreq can be overwrite >> by governor_userspace. For example: >> 1. The device driver assigned the devfreq governor to simple_ondemand >> by the function devfreq_add_device() and init the devfreq member >> void *data to a pointer of a static structure devfreq_simple_ondemand_data >> by the function devfreq_add_device(). >> 2. The user changed the devfreq governor to userspace by the command >> "echo userspace > /sys/class/devfreq/.../governor". >> 3. The governor userspace alloced a dynamic memory for the struct >> userspace_data and assigend the member void *data of devfreq to >> this memory by the function userspace_init(). >> 4. The user changed the devfreq governor back to simple_ondemand >> by the command "echo simple_ondemand > /sys/class/devfreq/.../governor". >> 5. The governor userspace exited and assigned the member void *data >> in the structure devfreq to NULL by the function userspace_exit(). >> 6. The governor simple_ondemand fetched the static information of >> devfreq_simple_ondemand_data in the function >> devfreq_simple_ondemand_func() but the member void *data of devfreq was >> assigned to NULL by the function userspace_exit(). >> 7. The information of upthreshold and downdifferential is lost >> and the governor simple_ondemand can't work correctly. >> >> The member void *data in the structure devfreq is designed for >> a static pointer used in a governor and inited by the function >> devfreq_add_device(). This patch add an element named governor_data >> in the devfreq structure which can be used by a governor(E.g userspace) >> who want to assign a private data to do some private things. >> >> Acked-by: MyungJoo Ham >> >> Signed-off-by: Kant Fan >> --- >> drivers/devfreq/governor_userspace.c | 12 ++++++------ >> include/linux/devfreq.h | 7 ++++--- >> 2 files changed, 10 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c >> index ab9db7adb3ad..d69672ccacc4 100644 >> --- a/drivers/devfreq/governor_userspace.c >> +++ b/drivers/devfreq/governor_userspace.c >> @@ -21,7 +21,7 @@ struct userspace_data { >> >> static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq) >> { >> - struct userspace_data *data = df->data; >> + struct userspace_data *data = df->governor_data; >> >> if (data->valid) >> *freq = data->user_frequency; >> @@ -40,7 +40,7 @@ static ssize_t set_freq_store(struct device *dev, struct device_attribute *attr, >> int err = 0; >> >> mutex_lock(&devfreq->lock); >> - data = devfreq->data; >> + data = devfreq->governor_data; >> >> sscanf(buf, "%lu", &wanted); >> data->user_frequency = wanted; >> @@ -60,7 +60,7 @@ static ssize_t set_freq_show(struct device *dev, >> int err = 0; >> >> mutex_lock(&devfreq->lock); >> - data = devfreq->data; >> + data = devfreq->governor_data; >> >> if (data->valid) >> err = sprintf(buf, "%lu\n", data->user_frequency); >> @@ -91,7 +91,7 @@ static int userspace_init(struct devfreq *devfreq) >> goto out; >> } >> data->valid = false; >> - devfreq->data = data; >> + devfreq->governor_data = data; >> >> err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group); >> out: >> @@ -107,8 +107,8 @@ static void userspace_exit(struct devfreq *devfreq) >> if (devfreq->dev.kobj.sd) >> sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group); >> >> - kfree(devfreq->data); >> - devfreq->data = NULL; >> + kfree(devfreq->governor_data); >> + devfreq->governor_data = NULL; >> } >> >> static int devfreq_userspace_handler(struct devfreq *devfreq, >> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h >> index 34aab4dd336c..d265af3fb0a4 100644 >> --- a/include/linux/devfreq.h >> +++ b/include/linux/devfreq.h >> @@ -152,8 +152,8 @@ struct devfreq_stats { >> * @max_state: count of entry present in the frequency table. >> * @previous_freq: previously configured frequency value. >> * @last_status: devfreq user device info, performance statistics >> - * @data: Private data of the governor. The devfreq framework does not >> - * touch this. >> + * @data: devfreq core pass to governors, governor should not change it. In addition, the devfreq driver pass the 'data' from devfreq driver to governor by using devfreq_add_device. I think that 'devfreq driver' is more proper * @data: devfreq driver pass to governors, governor should not change it. And then, there are extra changes required. diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 63347a5ae599..0c59b7978391 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -776,8 +776,7 @@ static void remove_sysfs_files(struct devfreq *devfreq, * @dev: the device to add devfreq feature. * @profile: device-specific profile to run devfreq. * @governor_name: name of the policy to choose frequency. - * @data: private data for the governor. The devfreq framework does not - * touch this value. + * @data: devfreq driver pass to governors, governor should not change it. */ struct devfreq *devfreq_add_device(struct device *dev, struct devfreq_dev_profile *profile, @@ -1011,8 +1010,7 @@ static void devm_devfreq_dev_release(struct device *dev, void *res) * @dev: the device to add devfreq feature. * @profile: device-specific profile to run devfreq. * @governor_name: name of the policy to choose frequency. - * @data: private data for the governor. The devfreq framework does not - * touch this value. + * @data: devfreq driver pass to governors, governor should not change it. * * This function manages automatically the memory of devfreq device using device * resource management and simplify the free operation for memory of devfreq -- Best Regards, Samsung Electronics Chanwoo Choi