Commit 1f8644d5 authored by Lukasz Luba's avatar Lukasz Luba Committed by Steven Price
Browse files

drm/panfrost: Add governor data with pre-defined thresholds 



The simple_ondemand devfreq governor uses two thresholds to decide about
the frequency change: upthreshold, downdifferential. These two tunable
change the behavior of the governor decision, e.g. how fast to increase
the frequency or how rapidly limit the frequency. This patch adds needed
governor data with thresholds values gathered experimentally in different
workloads.

Signed-off-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Reviewed-by: default avatarSteven Price <steven.price@arm.com>
Signed-off-by: default avatarSteven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210121170445.19761-1-lukasz.luba@arm.com
parent a78e7a51

drivers/gpu/drm/panfrost/panfrost_devfreq.c

+9 −1
Original line number Diff line number Diff line
@@ -130,8 +130,16 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev) 
	panfrost_devfreq_profile.initial_freq = cur_freq;

	dev_pm_opp_put(opp);



	/*

	 * Setup default thresholds for the simple_ondemand governor.

	 * The values are chosen based on experiments.

	 */

	pfdevfreq->gov_data.upthreshold = 45;

	pfdevfreq->gov_data.downdifferential = 5;



	devfreq = devm_devfreq_add_device(dev, &panfrost_devfreq_profile,

					  DEVFREQ_GOV_SIMPLE_ONDEMAND, NULL);

					  DEVFREQ_GOV_SIMPLE_ONDEMAND,

					  &pfdevfreq->gov_data);

	if (IS_ERR(devfreq)) {

		DRM_DEV_ERROR(dev, "Couldn't initialize GPU devfreq\n");

		ret = PTR_ERR(devfreq);

drivers/gpu/drm/panfrost/panfrost_devfreq.h

+2 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#ifndef __PANFROST_DEVFREQ_H__

#define __PANFROST_DEVFREQ_H__



#include <linux/devfreq.h>

#include <linux/spinlock.h>

#include <linux/ktime.h>
@@ -17,6 +18,7 @@ struct panfrost_devfreq { 
	struct devfreq *devfreq;

	struct opp_table *regulators_opp_table;

	struct thermal_cooling_device *cooling;

	struct devfreq_simple_ondemand_data gov_data;

	bool opp_of_table_added;



	ktime_t busy_time;