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 X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB506C4360C for ; Fri, 4 Oct 2019 17:05:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7790E20862 for ; Fri, 4 Oct 2019 17:05:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="WQlg5gH4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728671AbfJDRFQ (ORCPT ); Fri, 4 Oct 2019 13:05:16 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:44351 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728346AbfJDRFP (ORCPT ); Fri, 4 Oct 2019 13:05:15 -0400 Received: by mail-pf1-f195.google.com with SMTP id q21so4230751pfn.11 for ; Fri, 04 Oct 2019 10:05:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=7WcSZZeD+MKzcdOOdX6Ec/KkIbWWrsXycEBp6qCNW+Q=; b=WQlg5gH4TvsQj9MdH4CAkIkHVJMDvTHUa1YRY+efOo3XiTfU6eTv2KLfpwnZYiAnbh jsXNgUsvXEB2E9vHUz2xCUS2XUKcvEkrCkmEdyApnsA387upCYAadenA2X35WNE+fTAy bBsDLobadqgjfr43OVSLRRI70rCdpJO/95hiY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=7WcSZZeD+MKzcdOOdX6Ec/KkIbWWrsXycEBp6qCNW+Q=; b=fn8UpsYVqFHj8TgXPL82/hc/OjizY8+RyThBkb40ozTFU5JgGsKyaKzpAJ266CE0Rf 4GMOvDvnMWqleZ8ItAkhl4MoZU+GKEN7+Y50QmVLnknegZ28Kh4TqiDYYBuW2jt2uy0I M1rU7VNRFzON3TGAsZ/PeThymMiGIeT22D3tiS+9nGiyvSwfz9/zg565B0D2mB/aWFi2 24ysYd/fQ6WDbmQto2P5nJKLbn3AVeYK4E+am9Zka7JymtasNdWJQkxc1jPJlvaexwmL OWX5PZOuqsnOcT+WUcwSB/tg7eGgfnUJqe8rU9pXt6uflAv/xkUCHYg42kVWLOP0AAKg IomA== X-Gm-Message-State: APjAAAWnJTzsO+6tod2gaNqb8URtrR19qt1viT08atkaB4gfG1SrXVzx LwQuTRG7KGOkXeTGLh9WcHYA1Q== X-Google-Smtp-Source: APXvYqy+j0NZduXbdpAQagE8KCfWd4oDirEpNCra7THfxwooAIXXxa3Zu96+oAGzHo6st6ZVEDRlvw== X-Received: by 2002:a62:8142:: with SMTP id t63mr18450323pfd.246.1570208714816; Fri, 04 Oct 2019 10:05:14 -0700 (PDT) Received: from localhost ([2620:15c:202:1:4fff:7a6b:a335:8fde]) by smtp.gmail.com with ESMTPSA id 196sm12053609pfz.99.2019.10.04.10.05.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 04 Oct 2019 10:05:14 -0700 (PDT) Date: Fri, 4 Oct 2019 10:05:12 -0700 From: Matthias Kaehlcke To: Leonard Crestez Cc: Chanwoo Choi , MyungJoo Ham , Kyungmin Park , Artur =?utf-8?B?xZp3aWdvxYQ=?= , Saravana Kannan , Krzysztof Kozlowski , Alexandre Bailon , Georgi Djakov , Abel Vesa , Jacky Bai , Viresh Kumar , Lukasz Luba , NXP Linux Team , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v9 8/8] PM / devfreq: Use PM QoS for sysfs min/max_freq Message-ID: <20191004170512.GM87296@google.com> References: <62584a1e5c08d0f9254df505883fb220ba53d57b.1570044052.git.leonard.crestez@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <62584a1e5c08d0f9254df505883fb220ba53d57b.1570044052.git.leonard.crestez@nxp.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Wed, Oct 02, 2019 at 10:25:11PM +0300, Leonard Crestez wrote: > 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 > Reviewed-by: Matthias Kaehlcke > --- > drivers/devfreq/devfreq.c | 63 ++++++++++++++++++++++++++++----------- > include/linux/devfreq.h | 9 +++--- > 2 files changed, 51 insertions(+), 21 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 46f699b84a22..4ff5fbc4ee85 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); > /* scaling_max_freq can be zero on error */ > if (devfreq->scaling_max_freq) > *max_freq = min(*max_freq, devfreq->scaling_max_freq); > @@ -690,10 +686,18 @@ static void devfreq_dev_release(struct device *dev) > err); > > if (devfreq->profile->exit) > devfreq->profile->exit(devfreq->dev.parent); > > + err = dev_pm_qos_remove_request(&devfreq->user_max_freq_req); > + if (err) > + dev_warn(dev->parent, "Failed to remove DEV_PM_QOS_MAX_FREQUENCY request: %d\n", > + err); > + err = dev_pm_qos_remove_request(&devfreq->user_min_freq_req); > + if (err) > + dev_warn(dev->parent, "Failed to remove DEV_PM_QOS_MIN_FREQUENCY request: %d\n", > + err); > kfree(devfreq->time_in_state); > kfree(devfreq->trans_table); > mutex_destroy(&devfreq->lock); > kfree(devfreq); > } > @@ -758,18 +762,26 @@ struct devfreq *devfreq_add_device(struct device *dev, > devfreq->scaling_min_freq = find_available_min_freq(devfreq); > if (!devfreq->scaling_min_freq) { > 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) { > err = -EINVAL; > goto err_dev; > } > - devfreq->max_freq = devfreq->scaling_max_freq; > + > + err = dev_pm_qos_add_request(dev, &devfreq->user_min_freq_req, > + DEV_PM_QOS_MIN_FREQUENCY, 0); > + if (err < 0) > + goto err_dev; > + 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_dev; > > devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); > atomic_set(&devfreq->suspend_count, 0); > > devfreq->trans_table = kzalloc( > @@ -848,10 +860,16 @@ struct devfreq *devfreq_add_device(struct device *dev, > err_dev: > /* > * Cleanup path for errors that happen before registration. > * Otherwise we rely on devfreq_dev_release. > */ > + if (dev_pm_qos_request_active(&devfreq->user_max_freq_req)) > + if (dev_pm_qos_remove_request(&devfreq->user_max_freq_req)) > + dev_warn(dev, "Failed to remove DEV_PM_QOS_MAX_FREQUENCY request\n"); > + if (dev_pm_qos_request_active(&devfreq->user_min_freq_req)) > + if (dev_pm_qos_remove_request(&devfreq->user_min_freq_req)) > + dev_warn(dev, "Failed to remove DEV_PM_QOS_MIN_FREQUENCY request\n"); > kfree(devfreq->time_in_state); > kfree(devfreq->trans_table); > kfree(devfreq); > err_out: > return ERR_PTR(err); > @@ -1392,14 +1410,15 @@ static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr, > > 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, > @@ -1424,18 +1443,28 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, > > 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; > -- > 2.17.1 > Tested-by: Matthias Kaehlcke