From patchwork Thu Dec 5 10:05:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leonard Crestez X-Patchwork-Id: 11274603 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8B363930 for ; Thu, 5 Dec 2019 10:05:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68F1024654 for ; Thu, 5 Dec 2019 10:05:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728629AbfLEKFZ (ORCPT ); Thu, 5 Dec 2019 05:05:25 -0500 Received: from inva020.nxp.com ([92.121.34.13]:36602 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726096AbfLEKFY (ORCPT ); Thu, 5 Dec 2019 05:05:24 -0500 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 036F11A085A; Thu, 5 Dec 2019 11:05:23 +0100 (CET) Received: from inva024.eu-rdc02.nxp.com (inva024.eu-rdc02.nxp.com [134.27.226.22]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id E83CB1A04A8; Thu, 5 Dec 2019 11:05:22 +0100 (CET) Received: from fsr-ub1864-112.ea.freescale.net (fsr-ub1864-112.ea.freescale.net [10.171.82.98]) by inva024.eu-rdc02.nxp.com (Postfix) with ESMTP id 45EA62047A; Thu, 5 Dec 2019 11:05:22 +0100 (CET) From: Leonard Crestez To: "Rafael J. Wysocki" , Chanwoo Choi Cc: Matthias Kaehlcke , Kyungmin Park , MyungJoo Ham , =?utf-8?b?QXJ0dXIgxZp3aWdvxYQ=?= , Georgi Djakov , Jacky Bai , Viresh Kumar , NXP Linux Team , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 2/2] PM / devfreq: Use PM QoS for sysfs min/max_freq Date: Thu, 5 Dec 2019 12:05:07 +0200 Message-Id: <2b9eeb4e576c45269c01826f13c7811b876faa57.1575540224.git.leonard.crestez@nxp.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Switch the handling of min_freq and max_freq from sysfs to use the dev_pm_qos_request interface. Since PM QoS handles frequencies as kHz this change reduces the precision of min_freq and max_freq. This shouldn't introduce problems because frequencies which are not an integer number of kHz are likely not an integer number of Hz either. Try to ensure compatibility by rounding min values down and rounding max values up. Signed-off-by: Leonard Crestez Acked-by: Chanwoo Choi Reviewed-by: Matthias Kaehlcke Tested-by: Matthias Kaehlcke --- drivers/devfreq/devfreq.c | 76 ++++++++++++++++++++++++++++++--------- include/linux/devfreq.h | 9 ++--- 2 files changed, 64 insertions(+), 21 deletions(-) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index e8b943fc4259..bcb286509547 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -139,14 +139,10 @@ static void get_freq_range(struct devfreq *devfreq, *min_freq = max(*min_freq, (unsigned long)HZ_PER_KHZ * qos_min_freq); if (qos_max_freq != PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE) *max_freq = min(*max_freq, (unsigned long)HZ_PER_KHZ * qos_max_freq); - /* Apply constraints from sysfs */ - *min_freq = max(*min_freq, devfreq->min_freq); - *max_freq = min(*max_freq, devfreq->max_freq); - /* Apply constraints from OPP interface */ *min_freq = max(*min_freq, devfreq->scaling_min_freq); *max_freq = min(*max_freq, devfreq->scaling_max_freq); if (*min_freq > *max_freq) @@ -703,10 +699,23 @@ static void devfreq_dev_release(struct device *dev) DEV_PM_QOS_MIN_FREQUENCY); if (err && err != -ENOENT) dev_warn(dev->parent, "Failed to remove min_freq notifier: %d\n", err); + if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) { + err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req); + if (err) + dev_warn(dev->parent, + "Failed to remove max_freq request: %d\n", err); + } + if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) { + err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req); + if (err) + dev_warn(dev->parent, + "Failed to remove min_freq request: %d\n", err); + } + if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); mutex_destroy(&devfreq->lock); kfree(devfreq); @@ -776,19 +785,17 @@ struct devfreq *devfreq_add_device(struct device *dev, if (!devfreq->scaling_min_freq) { mutex_unlock(&devfreq->lock); err = -EINVAL; goto err_dev; } - devfreq->min_freq = devfreq->scaling_min_freq; devfreq->scaling_max_freq = find_available_max_freq(devfreq); if (!devfreq->scaling_max_freq) { mutex_unlock(&devfreq->lock); err = -EINVAL; goto err_dev; } - devfreq->max_freq = devfreq->scaling_max_freq; devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); atomic_set(&devfreq->suspend_count, 0); dev_set_name(&devfreq->dev, "devfreq%d", @@ -825,10 +832,20 @@ struct devfreq *devfreq_add_device(struct device *dev, srcu_init_notifier_head(&devfreq->transition_notifier_list); mutex_unlock(&devfreq->lock); + err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req, + DEV_PM_QOS_MIN_FREQUENCY, 0); + if (err < 0) + goto err_devfreq; + err = dev_pm_qos_add_request(dev, &devfreq->user_max_freq_req, + DEV_PM_QOS_MAX_FREQUENCY, + PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE); + if (err < 0) + goto err_devfreq; + devfreq->nb_min.notifier_call = qos_min_notifier_call; err = dev_pm_qos_add_notifier(devfreq->dev.parent, &devfreq->nb_min, DEV_PM_QOS_MIN_FREQUENCY); if (err) goto err_devfreq; @@ -1418,18 +1435,26 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, { struct devfreq *df = to_devfreq(dev); unsigned long value; int ret; + /* + * Protect against theoretical sysfs writes between + * device_add and dev_pm_qos_add_request + */ + if (!dev_pm_qos_request_active(&df->user_min_freq_req)) + return -EINVAL; + ret = sscanf(buf, "%lu", &value); if (ret != 1) return -EINVAL; - mutex_lock(&df->lock); - df->min_freq = value; - update_devfreq(df); - mutex_unlock(&df->lock); + /* Round down to kHz for PM QoS */ + ret = dev_pm_qos_update_request(&df->user_min_freq_req, + value / HZ_PER_KHZ); + if (ret < 0) + return ret; return count; } static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, @@ -1450,22 +1475,39 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, { struct devfreq *df = to_devfreq(dev); unsigned long value; int ret; + /* + * Protect against theoretical sysfs writes between + * device_add and dev_pm_qos_add_request + */ + if (!dev_pm_qos_request_active(&df->user_max_freq_req)) + return -EINVAL; + ret = sscanf(buf, "%lu", &value); if (ret != 1) return -EINVAL; - mutex_lock(&df->lock); - - if (!value) - value = ULONG_MAX; + /* + * PM QoS frequencies are in kHz so we need to convert. Convert by + * rounding upwards so that the acceptable interval never shrinks. + * + * For example if the user writes "666666666" to sysfs this value will + * be converted to 666667 kHz and back to 666667000 Hz before an OPP + * lookup, this ensures that an OPP of 666666666Hz is still accepted. + * + * A value of zero means "no limit". + */ + if (value) + value = DIV_ROUND_UP(value, HZ_PER_KHZ); + else + value = PM_QOS_MAX_FREQUENCY_DEFAULT_VALUE; - df->max_freq = value; - update_devfreq(df); - mutex_unlock(&df->lock); + ret = dev_pm_qos_update_request(&df->user_max_freq_req, value); + if (ret < 0) + return ret; return count; } static DEVICE_ATTR_RW(min_freq); diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index 8b92ccbd1962..fb376b5b7281 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -11,10 +11,11 @@ #define __LINUX_DEVFREQ_H__ #include #include #include +#include #define DEVFREQ_NAME_LEN 16 /* DEVFREQ governor name */ #define DEVFREQ_GOV_SIMPLE_ONDEMAND "simple_ondemand" @@ -121,12 +122,12 @@ struct devfreq_dev_profile { * devfreq.nb to the corresponding register notifier call chain. * @work: delayed work for load monitoring. * @previous_freq: previously configured frequency value. * @data: Private data of the governor. The devfreq framework does not * touch this. - * @min_freq: Limit minimum frequency requested by user (0: none) - * @max_freq: Limit maximum frequency requested by user (0: none) + * @user_min_freq_req: PM QoS minimum frequency request from user (via sysfs) + * @user_max_freq_req: PM QoS maximum frequency request from user (via sysfs) * @scaling_min_freq: Limit minimum frequency requested by OPP interface * @scaling_max_freq: Limit maximum frequency requested by OPP interface * @stop_polling: devfreq polling status of a device. * @suspend_freq: frequency of a device set during suspend phase. * @resume_freq: frequency of a device set in resume phase. @@ -161,12 +162,12 @@ struct devfreq { unsigned long previous_freq; struct devfreq_dev_status last_status; void *data; /* private data for governors */ - unsigned long min_freq; - unsigned long max_freq; + struct dev_pm_qos_request user_min_freq_req; + struct dev_pm_qos_request user_max_freq_req; unsigned long scaling_min_freq; unsigned long scaling_max_freq; bool stop_polling; unsigned long suspend_freq;