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,URIBL_BLOCKED, 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 3C10BC3A5A6 for ; Thu, 19 Sep 2019 19:59:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01C5D207FC for ; Thu, 19 Sep 2019 19:59:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="cMPAoE2C" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390554AbfIST7H (ORCPT ); Thu, 19 Sep 2019 15:59:07 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:46452 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390537AbfIST7H (ORCPT ); Thu, 19 Sep 2019 15:59:07 -0400 Received: by mail-pg1-f193.google.com with SMTP id a3so2459826pgm.13 for ; Thu, 19 Sep 2019 12:59:05 -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=hhfYGawXnW6uZYoOjBbGCOHapRV4NV4Ipk+mhG/LMb4=; b=cMPAoE2CVW4AHsyImxaghCHK23cQoodnjiTjkJtwnGtLNE2+IHxFvKJ9H04OIAyo2S 4/nNZzIBT1UIoxQVEGfj+dfnHnOBETTXEjCXbrxMDswzMk8cBD3rBOUkvUDgZLiRRuF7 HCfQaDrV6cM/MdqhbD36FvXKfn+XsMM+BYuB8= 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=hhfYGawXnW6uZYoOjBbGCOHapRV4NV4Ipk+mhG/LMb4=; b=slzjX2StTJPzyBmyksAeEFztn4/hhggfvB1ROLeZrtRruLrI99EjwOdMJAKFP7BJcn zwAy78bURbk3aoZfOcuE/xq7E7t7pneIFX4dXhHCEa/07Y/anbQl36JEfIPlb8wyhheq nIjKanNlzXruF1wQ1EtDQ4jkZjUTCJj0kqe6l/bFUfaEhDENP8PNITCwOicj5XhlpLE2 mgc3ltbobcPOKX7Y9Kp5p/wAr3f7xRr6FdV1NQpwhAOkMO5BT/XF6Honw6RpsWw2jCJ+ 3IsBPTIkorxsQvodz1Ht6kYGtReBC1BgVshcG9U9fUibKS+Xs5jPdDko3z49T9uR0Ptq TtgA== X-Gm-Message-State: APjAAAWfu0Zit+68/4POrMzS99qcbUrbCnVGLUOcECtzshkb/PCbbXmt sLgtRamgxtih3XApUCUIeu9aUw== X-Google-Smtp-Source: APXvYqzHI02bCChGq61Le1kggMWELJvMhyYhBSfPs7Bhm47tqwyAWhdAowbHugKpU4p0XwGvghPeJQ== X-Received: by 2002:a63:ba47:: with SMTP id l7mr10690493pgu.201.1568923144882; Thu, 19 Sep 2019 12:59:04 -0700 (PDT) Received: from localhost ([2620:15c:202:1:75a:3f6e:21d:9374]) by smtp.gmail.com with ESMTPSA id j4sm11101737pfn.29.2019.09.19.12.59.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 19 Sep 2019 12:59:04 -0700 (PDT) Date: Thu, 19 Sep 2019 12:59:02 -0700 From: Matthias Kaehlcke To: Leonard Crestez Cc: MyungJoo Ham , Kyungmin Park , Chanwoo Choi , Artur =?utf-8?B?xZp3aWdvxYQ=?= , Saravana Kannan , Krzysztof Kozlowski , Alexandre Bailon , Georgi Djakov , Abel Vesa , Jacky Bai , Viresh Kumar , linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 7/8] PM / devfreq: Use dev_pm_qos for sysfs min/max_freq Message-ID: <20190919195902.GX133864@google.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: 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, Sep 18, 2019 at 03:18:26AM +0300, Leonard Crestez wrote: > Switch the handling of min_freq and max_freq from sysfs to use the > dev_pm_qos interface. nit: PM QoS? if you agree please change all instances in comments. > Since dev_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 compatibilitity by rounding min values down and rounding > max values up. > > Signed-off-by: Leonard Crestez > --- > drivers/devfreq/devfreq.c | 51 +++++++++++++++++++++++++-------------- > include/linux/devfreq.h | 9 ++++--- > 2 files changed, 38 insertions(+), 22 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index d8d57318b12c..7977bad93949 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -132,14 +132,10 @@ static void devfreq_get_freq_range(struct devfreq *devfreq, > *min_freq = max(*min_freq, HZ_PER_KHZ * (unsigned long)dev_pm_qos_read_value( > devfreq->dev.parent, DEV_PM_QOS_MIN_FREQUENCY)); > *max_freq = min(*max_freq, HZ_PER_KHZ * (unsigned long)dev_pm_qos_read_value( > devfreq->dev.parent, DEV_PM_QOS_MAX_FREQUENCY)); > > - /* constraints from sysfs: */ > - *min_freq = max(*min_freq, devfreq->min_freq); > - *max_freq = min(*max_freq, devfreq->max_freq); > - > /* 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); > @@ -675,10 +671,12 @@ static void devfreq_dev_release(struct device *dev) > DEV_PM_QOS_MIN_FREQUENCY); > > if (devfreq->profile->exit) > devfreq->profile->exit(devfreq->dev.parent); > > + dev_pm_qos_remove_request(&devfreq->max_freq_req); > + dev_pm_qos_remove_request(&devfreq->min_freq_req); mega-nit: keep common mix/max order since it doesn't really matter here? > mutex_destroy(&devfreq->lock); > kfree(devfreq->time_in_state); > kfree(devfreq->trans_table); > kfree(devfreq); > } > @@ -743,18 +741,28 @@ 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; > + > + /* dev_pm_qos requests for min/max freq from sysfs */ > + err = dev_pm_qos_add_request(dev, &devfreq->min_freq_req, > + DEV_PM_QOS_MIN_FREQUENCY, 0); > + if (err < 0) { > + goto err_dev; > + } no curly braces needed for single line. > + err = dev_pm_qos_add_request(dev, &devfreq->max_freq_req, > + DEV_PM_QOS_MAX_FREQUENCY, S32_MAX); > + if (err < 0) { > + goto err_dev; > + } ditto > devfreq->suspend_freq = dev_pm_opp_get_suspend_opp_freq(dev); > atomic_set(&devfreq->suspend_count, 0); > > devfreq->trans_table = kzalloc( > @@ -833,10 +841,14 @@ struct devfreq *devfreq_add_device(struct device *dev, > mutex_unlock(&devfreq_list_lock); > err_devfreq: > devfreq_remove_device(devfreq); > return ERR_PTR(err); > err_dev: > + if (dev_pm_qos_request_active(&devfreq->max_freq_req)) > + dev_pm_qos_remove_request(&devfreq->max_freq_req); > + if (dev_pm_qos_request_active(&devfreq->min_freq_req)) > + dev_pm_qos_remove_request(&devfreq->min_freq_req); > kfree(devfreq->time_in_state); > kfree(devfreq->trans_table); > kfree(devfreq); > err_out: > return ERR_PTR(err); > @@ -1397,14 +1409,17 @@ 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 dev_pm_qos */ > + if (value) > + value = value / HZ_PER_KHZ; > + > + ret = dev_pm_qos_update_request(&df->min_freq_req, value); > + if (ret < 0) > + return ret; > > return count; > } > > static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, > @@ -1429,19 +1444,19 @@ 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); > - > - /* Interpret zero as "don't care" */ > - if (!value) > - value = ULONG_MAX; > + /* round up to kHz for dev_pm_qos and interpret zero as "don't care" */ > + if (value) > + value = DIV_ROUND_UP(value, HZ_PER_KHZ); > + else > + value = S32_MAX; > > - df->max_freq = value; > - update_devfreq(df); > - mutex_unlock(&df->lock); > + ret = dev_pm_qos_update_request(&df->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 dac0dffeabb4..4b5cc80abbe3 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) > + * @min_freq_req: Limit minimum frequency requested by user (0: none) '(0: none)' is not correct anymore. Maybe also say that it's a PM QoS request? Since you are already changing the variable name it could be a good opportunity to make it more specific, i.e. make clear that it's the userspace constraint. e.g. min_freq_req_user user_min_freq_req min_freq_user_req or struct { struct { min; max; } user; struct { min; max; } scaling; // not a great name, but that's what it is currently ... } freq_constraints; > + * @max_freq_req: Limit maximum frequency requested by user (0: none) > * @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 min_freq_req; > + struct dev_pm_qos_request max_freq_req; > unsigned long scaling_min_freq; > unsigned long scaling_max_freq; > bool stop_polling; > > unsigned long suspend_freq;