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 3D311C3A5A6 for ; Thu, 19 Sep 2019 18:07:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 092A621928 for ; Thu, 19 Sep 2019 18:07:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Dr2/UNlN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392010AbfISSH1 (ORCPT ); Thu, 19 Sep 2019 14:07:27 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:38223 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391305AbfISSH1 (ORCPT ); Thu, 19 Sep 2019 14:07:27 -0400 Received: by mail-pg1-f195.google.com with SMTP id x10so2332027pgi.5 for ; Thu, 19 Sep 2019 11:07:26 -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=6zOXFEBSPDZErMe9LV7l8EKhi6rWrhgSCyFAiesvqHY=; b=Dr2/UNlNG3sv0cx7PB+rSh4YJYAyZuRnRj20BMJkFtIVY13eSorTbe31N66kTu2+rL ivGfQuS8py4c7wiZLTrme+D2Ln2F5DvEhuk1N/mDeECEyc8E7Emb/awKK8T7ajiiB9ui qIpewSGPBDXuBhdcAkJAYnXcyi9XA4KQW9LWc= 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=6zOXFEBSPDZErMe9LV7l8EKhi6rWrhgSCyFAiesvqHY=; b=jMmye28r80zQsbhs3hda/qNi8Qnq8fMGPIRzrFU5T/TmdWD0d5Dnyw2Q7LexB51IMn 3Yb6o1x/OnPlLKV4DWQ8EEMUpZR7U2g7ODl6BRzOuHVoBGdsEP73c3zlhgee/JTFSFg0 +sFXe3IrcsgmoxYcSu0wDP405BtrLM8lm6tI5Lz0B5CqNnP0jcSZrTV9vKy3IkPlmOXU 0+k2DZ4/pgckxlMacbqGXLmzs8TR78FWRRZTuruOEX1EFBqRT/zb0G+4j78OeBSR8uMA NbEp59iiCFUIu2DjITGKZGvRDrGh/JhGcRvIOGoc4pvCyOEXkCrS+4AkIS2vNAuG0WlE yFEA== X-Gm-Message-State: APjAAAXF6Zxw+NN8tvd1qoVyfXu/WapYIi7sTKbHKt1kpIKU7V5NUUf7 IFbs92w6pu6FugASrrplsjuU+g== X-Google-Smtp-Source: APXvYqwxu4qKbBsqkCVgsollebgqQKv9fNb34P5+qEIWvXb5p2z0UPMn14XUI3+rXP6gBriLWKt2FA== X-Received: by 2002:a63:4c5c:: with SMTP id m28mr10896199pgl.333.1568916445963; Thu, 19 Sep 2019 11:07:25 -0700 (PDT) Received: from localhost ([2620:15c:202:1:75a:3f6e:21d:9374]) by smtp.gmail.com with ESMTPSA id l23sm8059715pgj.53.2019.09.19.11.07.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 19 Sep 2019 11:07:24 -0700 (PDT) Date: Thu, 19 Sep 2019 11:07:22 -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 5/8] PM / devfreq: Introduce devfreq_get_freq_range Message-ID: <20190919180722.GT133864@google.com> References: <730613d6f7182c6a6784fd509d6324f28be2cac3.1568764439.git.leonard.crestez@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <730613d6f7182c6a6784fd509d6324f28be2cac3.1568764439.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 Hi Leonard, On Wed, Sep 18, 2019 at 03:18:24AM +0300, Leonard Crestez wrote: > Moving handling of min/max freq to a single function and call it from > update_devfreq and for printing min/max freq values in sysfs. > > This changes the behavior of out-of-range min_freq/max_freq: clamping > is now done at evaluation time. This means that if an out-of-range > constraint is imposed by sysfs and it later becomes valid then it will > be enforced. > > Signed-off-by: Leonard Crestez > --- > drivers/devfreq/devfreq.c | 111 +++++++++++++++++++++----------------- > 1 file changed, 63 insertions(+), 48 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 860cbbab476c..51a4179e2c69 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -24,10 +24,12 @@ > #include > #include > #include > #include "governor.h" > > +#define HZ_PER_KHZ 1000 > + > #define CREATE_TRACE_POINTS > #include > > static struct class *devfreq_class; > > @@ -96,10 +98,50 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq) > dev_pm_opp_put(opp); > > return max_freq; > } > > +/** > + * devfreq_get_freq_range() - Get the current freq range > + * @devfreq: the devfreq instance > + * @min_freq: the min frequency > + * @max_freq: the max frequency > + * > + * This takes into consideration all constraints. > + */ > +static void devfreq_get_freq_range(struct devfreq *devfreq, > + unsigned long *min_freq, > + unsigned long *max_freq) > +{ > + unsigned long *freq_table = devfreq->profile->freq_table; > + > + lockdep_assert_held(&devfreq->lock); > + > + /* Init min/max frequency from freq table */ > + if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) { > + *min_freq = freq_table[0]; > + *max_freq = freq_table[devfreq->profile->max_state - 1]; > + } else { > + *min_freq = freq_table[devfreq->profile->max_state - 1]; > + *max_freq = freq_table[0]; > + } > + > + /* constraints from sysfs: */ > + *min_freq = max(*min_freq, devfreq->min_freq); > + *max_freq = min(*max_freq, devfreq->max_freq); > + > + /* constraints from opp interface: */ nit: OPP > + *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); > + > + /* max_freq takes precedence over min_freq */ > + if (*min_freq > *max_freq) > + *min_freq = *max_freq; > +} > + > /** > * devfreq_get_freq_level() - Lookup freq_table for the frequency > * @devfreq: the devfreq instance > * @freq: the target frequency > */ > @@ -349,21 +391,13 @@ int update_devfreq(struct devfreq *devfreq) > > /* Reevaluate the proper frequency */ > err = devfreq->governor->get_target_freq(devfreq, &freq); > if (err) > return err; > + devfreq_get_freq_range(devfreq, &min_freq, &max_freq); > > - /* > - * Adjust the frequency with user freq, QoS and available freq. > - * > - * List from the highest priority > - * max_freq > - * min_freq > - */ > - max_freq = min(devfreq->scaling_max_freq, devfreq->max_freq); > - min_freq = max(devfreq->scaling_min_freq, devfreq->min_freq); > - > + /* max freq takes priority over min freq */ > if (freq < min_freq) { > freq = min_freq; > flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */ > } > if (freq > max_freq) { > @@ -1293,40 +1327,28 @@ 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); > - > - if (value) { > - if (value > df->max_freq) { > - ret = -EINVAL; > - goto unlock; > - } > - } else { > - unsigned long *freq_table = df->profile->freq_table; > - > - /* Get minimum frequency according to sorting order */ > - if (freq_table[0] < freq_table[df->profile->max_state - 1]) > - value = freq_table[0]; > - else > - value = freq_table[df->profile->max_state - 1]; > - } > - > df->min_freq = value; > update_devfreq(df); > - ret = count; > -unlock: > mutex_unlock(&df->lock); > - return ret; > + > + return count; > } > > static ssize_t min_freq_show(struct device *dev, struct device_attribute *attr, > char *buf) > { > struct devfreq *df = to_devfreq(dev); > + unsigned long min_freq, max_freq; > > - return sprintf(buf, "%lu\n", max(df->scaling_min_freq, df->min_freq)); > + mutex_lock(&df->lock); > + devfreq_get_freq_range(df, &min_freq, &max_freq); > + mutex_unlock(&df->lock); > + > + return sprintf(buf, "%lu\n", min_freq); > } > > static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, > const char *buf, size_t count) > { > @@ -1338,40 +1360,33 @@ static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr, > if (ret != 1) > return -EINVAL; > > mutex_lock(&df->lock); > > - if (value) { > - if (value < df->min_freq) { > - ret = -EINVAL; > - goto unlock; > - } > - } else { > - unsigned long *freq_table = df->profile->freq_table; > - > - /* Get maximum frequency according to sorting order */ > - if (freq_table[0] < freq_table[df->profile->max_state - 1]) > - value = freq_table[df->profile->max_state - 1]; > - else > - value = freq_table[0]; > - } > + /* Interpret zero as "don't care" */ > + if (!value) > + value = ULONG_MAX; > > df->max_freq = value; > update_devfreq(df); > - ret = count; > -unlock: > mutex_unlock(&df->lock); > - return ret; > + > + return count; > } > static DEVICE_ATTR_RW(min_freq); > > static ssize_t max_freq_show(struct device *dev, struct device_attribute *attr, > char *buf) > { > struct devfreq *df = to_devfreq(dev); > + unsigned long min_freq, max_freq; > + > + mutex_lock(&df->lock); > + devfreq_get_freq_range(df, &min_freq, &max_freq); > + mutex_unlock(&df->lock); > > - return sprintf(buf, "%lu\n", min(df->scaling_max_freq, df->max_freq)); > + return sprintf(buf, "%lu\n", max_freq); > } > static DEVICE_ATTR_RW(max_freq); > > static ssize_t available_frequencies_show(struct device *d, > struct device_attribute *attr, Nice, having the constraint evaluation in a single function makes it easier to follow the code. Clamping userspace constraints at runtime makes sense. Reviewed-by: Matthias Kaehlcke I plan to take a look at the rest of the series, but probably won't find time for all of it before next week.