Linux-PM Archive on lore.kernel.org
 help / color / Atom feed
From: Chanwoo Choi <cw00.choi@samsung.com>
To: Leonard Crestez <leonard.crestez@nxp.com>,
	MyungJoo Ham <myungjoo.ham@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: "Matthias Kaehlcke" <mka@chromium.org>,
	"Artur Świgoń" <a.swigon@partner.samsung.com>,
	"Saravana Kannan" <saravanak@google.com>,
	"Krzysztof Kozlowski" <krzk@kernel.org>,
	"Alexandre Bailon" <abailon@baylibre.com>,
	"Georgi Djakov" <georgi.djakov@linaro.org>,
	"Abel Vesa" <abel.vesa@nxp.com>, "Jacky Bai" <ping.bai@nxp.com>,
	"Viresh Kumar" <viresh.kumar@linaro.org>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v10 09/11] PM / devfreq: Introduce get_freq_range helper
Date: Mon, 11 Nov 2019 14:56:48 +0900
Message-ID: <b6662a88-af9b-6948-a1ea-921a10ca937d@samsung.com> (raw)
In-Reply-To: <6fd2ab4b54f5cd3a02b3f5f8aae5e776485441e3.1572556786.git.leonard.crestez@nxp.com>

On 11/1/19 6:34 AM, 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 <leonard.crestez@nxp.com>
> Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
> ---
>  drivers/devfreq/devfreq.c | 108 +++++++++++++++++++++-----------------
>  1 file changed, 60 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index ab12fd22aa08..ba3b53ee23fd 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -96,10 +96,51 @@ static unsigned long find_available_max_freq(struct devfreq *devfreq)
>  		dev_pm_opp_put(opp);
>  
>  	return max_freq;
>  }
>  
> +/**
> + * 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 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);
> +
> +	/*
> +	 * Initialize minimum/maximum frequency from freq table.
> +	 * The devfreq drivers can initialize this in either ascending or
> +	 * descending order and devfreq core supports both.
> +	 */
> +	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];
> +	}
> +
> +	/* 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)
> +		*min_freq = *max_freq;
> +}
> +
>  /**
>   * devfreq_get_freq_level() - Lookup freq_table for the frequency
>   * @devfreq:	the devfreq instance
>   * @freq:	the target frequency
>   */
> @@ -348,20 +389,11 @@ int update_devfreq(struct devfreq *devfreq)
>  
>  	/* Reevaluate the proper frequency */
>  	err = devfreq->governor->get_target_freq(devfreq, &freq);
>  	if (err)
>  		return err;
> -
> -	/*
> -	 * 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);
> +	get_freq_range(devfreq, &min_freq, &max_freq);
>  
>  	if (freq < min_freq) {
>  		freq = min_freq;
>  		flags &= ~DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use GLB */
>  	}
> @@ -1292,40 +1324,28 @@ 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);
> +	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)
>  {
> @@ -1337,40 +1357,32 @@ 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];
> -	}
> +	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);
> +	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,
> 

Applied it because it doesn't depend on the pm_qos feature.

-- 
Best Regards,
Chanwoo Choi
Samsung Electronics

  reply index

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-31 21:34 [PATCH v10] PM / devfreq: Add dev_pm_qos support Leonard Crestez
2019-10-31 21:34 ` [PATCH v10 01/11] PM / devfreq: Fix devfreq_notifier_call returning errno Leonard Crestez
2019-11-11  5:55   ` Chanwoo Choi
2019-10-31 21:34 ` [PATCH v10 02/11] PM / devfreq: Set scaling_max_freq to max on OPP notifier error Leonard Crestez
2019-11-11  5:55   ` Chanwoo Choi
2019-10-31 21:34 ` [PATCH v10 03/11] PM / devfreq: Split device_register usage Leonard Crestez
2019-10-31 21:34 ` [PATCH v10 04/11] PM / devfreq: Move more initialization before registration Leonard Crestez
2019-10-31 21:34 ` [PATCH v10 05/11] PM / devfreq: Don't take lock in devfreq_add_device Leonard Crestez
2019-10-31 21:34 ` [PATCH v10 06/11] PM / QoS: Reorder pm_qos/freq_qos/dev_pm_qos structs Leonard Crestez
2019-11-01  2:13   ` Chanwoo Choi
2019-11-01 14:45     ` Leonard Crestez
2019-11-11  5:52       ` Chanwoo Choi
2019-10-31 21:34 ` [PATCH v10 07/11] PM / QoS: Export _freq_qos_apply Leonard Crestez
2019-10-31 21:34 ` [PATCH v10 08/11] PM / QoS: Restore DEV_PM_QOS_MIN/MAX_FREQUENCY Leonard Crestez
2019-10-31 21:34 ` [PATCH v10 09/11] PM / devfreq: Introduce get_freq_range helper Leonard Crestez
2019-11-11  5:56   ` Chanwoo Choi [this message]
2019-11-11 14:37     ` Leonard Crestez
2019-10-31 21:34 ` [PATCH v10 10/11] PM / devfreq: Add PM QoS support Leonard Crestez
2019-10-31 21:34 ` [PATCH v10 11/11] PM / devfreq: Use PM QoS for sysfs min/max_freq Leonard Crestez

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=b6662a88-af9b-6948-a1ea-921a10ca937d@samsung.com \
    --to=cw00.choi@samsung.com \
    --cc=a.swigon@partner.samsung.com \
    --cc=abailon@baylibre.com \
    --cc=abel.vesa@nxp.com \
    --cc=georgi.djakov@linaro.org \
    --cc=krzk@kernel.org \
    --cc=kyungmin.park@samsung.com \
    --cc=leonard.crestez@nxp.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-imx@nxp.com \
    --cc=linux-pm@vger.kernel.org \
    --cc=mka@chromium.org \
    --cc=myungjoo.ham@samsung.com \
    --cc=ping.bai@nxp.com \
    --cc=rjw@rjwysocki.net \
    --cc=saravanak@google.com \
    --cc=viresh.kumar@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-PM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pm/0 linux-pm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pm linux-pm/ https://lore.kernel.org/linux-pm \
		linux-pm@vger.kernel.org
	public-inbox-index linux-pm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git