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v6.8
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  drivers/cpufreq/cpufreq_conservative.c
  4 *
  5 *  Copyright (C)  2001 Russell King
  6 *            (C)  2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
  7 *                      Jun Nakajima <jun.nakajima@intel.com>
  8 *            (C)  2009 Alexander Clouter <alex@digriz.org.uk>
 
 
 
 
  9 */
 10
 11#include <linux/slab.h>
 12#include "cpufreq_governor.h"
 13
 14struct cs_policy_dbs_info {
 15	struct policy_dbs_info policy_dbs;
 16	unsigned int down_skip;
 17	unsigned int requested_freq;
 18};
 19
 20static inline struct cs_policy_dbs_info *to_dbs_info(struct policy_dbs_info *policy_dbs)
 21{
 22	return container_of(policy_dbs, struct cs_policy_dbs_info, policy_dbs);
 23}
 24
 25struct cs_dbs_tuners {
 26	unsigned int down_threshold;
 27	unsigned int freq_step;
 28};
 29
 30/* Conservative governor macros */
 31#define DEF_FREQUENCY_UP_THRESHOLD		(80)
 32#define DEF_FREQUENCY_DOWN_THRESHOLD		(20)
 33#define DEF_FREQUENCY_STEP			(5)
 34#define DEF_SAMPLING_DOWN_FACTOR		(1)
 35#define MAX_SAMPLING_DOWN_FACTOR		(10)
 36
 37static inline unsigned int get_freq_step(struct cs_dbs_tuners *cs_tuners,
 38					 struct cpufreq_policy *policy)
 39{
 40	unsigned int freq_step = (cs_tuners->freq_step * policy->max) / 100;
 41
 42	/* max freq cannot be less than 100. But who knows... */
 43	if (unlikely(freq_step == 0))
 44		freq_step = DEF_FREQUENCY_STEP;
 45
 46	return freq_step;
 47}
 48
 49/*
 50 * Every sampling_rate, we check, if current idle time is less than 20%
 51 * (default), then we try to increase frequency. Every sampling_rate *
 52 * sampling_down_factor, we check, if current idle time is more than 80%
 53 * (default), then we try to decrease frequency
 54 *
 55 * Frequency updates happen at minimum steps of 5% (default) of maximum
 56 * frequency
 57 */
 58static unsigned int cs_dbs_update(struct cpufreq_policy *policy)
 59{
 60	struct policy_dbs_info *policy_dbs = policy->governor_data;
 61	struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
 62	unsigned int requested_freq = dbs_info->requested_freq;
 63	struct dbs_data *dbs_data = policy_dbs->dbs_data;
 64	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
 65	unsigned int load = dbs_update(policy);
 66	unsigned int freq_step;
 67
 68	/*
 69	 * break out if we 'cannot' reduce the speed as the user might
 70	 * want freq_step to be zero
 71	 */
 72	if (cs_tuners->freq_step == 0)
 73		goto out;
 74
 75	/*
 76	 * If requested_freq is out of range, it is likely that the limits
 77	 * changed in the meantime, so fall back to current frequency in that
 78	 * case.
 79	 */
 80	if (requested_freq > policy->max || requested_freq < policy->min) {
 81		requested_freq = policy->cur;
 82		dbs_info->requested_freq = requested_freq;
 83	}
 84
 85	freq_step = get_freq_step(cs_tuners, policy);
 86
 87	/*
 88	 * Decrease requested_freq one freq_step for each idle period that
 89	 * we didn't update the frequency.
 90	 */
 91	if (policy_dbs->idle_periods < UINT_MAX) {
 92		unsigned int freq_steps = policy_dbs->idle_periods * freq_step;
 93
 94		if (requested_freq > policy->min + freq_steps)
 95			requested_freq -= freq_steps;
 96		else
 97			requested_freq = policy->min;
 98
 99		policy_dbs->idle_periods = UINT_MAX;
100	}
101
102	/* Check for frequency increase */
103	if (load > dbs_data->up_threshold) {
104		dbs_info->down_skip = 0;
105
106		/* if we are already at full speed then break out early */
107		if (requested_freq == policy->max)
108			goto out;
109
110		requested_freq += freq_step;
111		if (requested_freq > policy->max)
112			requested_freq = policy->max;
113
114		__cpufreq_driver_target(policy, requested_freq,
115					CPUFREQ_RELATION_HE);
116		dbs_info->requested_freq = requested_freq;
117		goto out;
118	}
119
120	/* if sampling_down_factor is active break out early */
121	if (++dbs_info->down_skip < dbs_data->sampling_down_factor)
122		goto out;
123	dbs_info->down_skip = 0;
124
125	/* Check for frequency decrease */
126	if (load < cs_tuners->down_threshold) {
 
127		/*
128		 * if we cannot reduce the frequency anymore, break out early
129		 */
130		if (requested_freq == policy->min)
131			goto out;
132
133		if (requested_freq > freq_step)
134			requested_freq -= freq_step;
 
135		else
136			requested_freq = policy->min;
137
138		__cpufreq_driver_target(policy, requested_freq,
139					CPUFREQ_RELATION_LE);
140		dbs_info->requested_freq = requested_freq;
141	}
142
143 out:
144	return dbs_data->sampling_rate;
145}
146
 
 
 
 
 
 
 
147/************************** sysfs interface ************************/
 
148
149static ssize_t sampling_down_factor_store(struct gov_attr_set *attr_set,
150					  const char *buf, size_t count)
151{
152	struct dbs_data *dbs_data = to_dbs_data(attr_set);
153	unsigned int input;
154	int ret;
155	ret = sscanf(buf, "%u", &input);
156
157	if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
158		return -EINVAL;
159
160	dbs_data->sampling_down_factor = input;
161	return count;
162}
163
164static ssize_t up_threshold_store(struct gov_attr_set *attr_set,
165				  const char *buf, size_t count)
166{
167	struct dbs_data *dbs_data = to_dbs_data(attr_set);
168	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
169	unsigned int input;
170	int ret;
171	ret = sscanf(buf, "%u", &input);
172
173	if (ret != 1 || input > 100 || input <= cs_tuners->down_threshold)
174		return -EINVAL;
175
176	dbs_data->up_threshold = input;
177	return count;
178}
179
180static ssize_t down_threshold_store(struct gov_attr_set *attr_set,
181				    const char *buf, size_t count)
182{
183	struct dbs_data *dbs_data = to_dbs_data(attr_set);
184	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
185	unsigned int input;
186	int ret;
187	ret = sscanf(buf, "%u", &input);
188
189	/* cannot be lower than 1 otherwise freq will not fall */
190	if (ret != 1 || input < 1 || input >= dbs_data->up_threshold)
 
191		return -EINVAL;
192
193	cs_tuners->down_threshold = input;
194	return count;
195}
196
197static ssize_t ignore_nice_load_store(struct gov_attr_set *attr_set,
198				      const char *buf, size_t count)
199{
200	struct dbs_data *dbs_data = to_dbs_data(attr_set);
201	unsigned int input;
202	int ret;
203
204	ret = sscanf(buf, "%u", &input);
205	if (ret != 1)
206		return -EINVAL;
207
208	if (input > 1)
209		input = 1;
210
211	if (input == dbs_data->ignore_nice_load) /* nothing to do */
212		return count;
213
214	dbs_data->ignore_nice_load = input;
215
216	/* we need to re-evaluate prev_cpu_idle */
217	gov_update_cpu_data(dbs_data);
218
219	return count;
220}
221
222static ssize_t freq_step_store(struct gov_attr_set *attr_set, const char *buf,
223			       size_t count)
224{
225	struct dbs_data *dbs_data = to_dbs_data(attr_set);
226	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
227	unsigned int input;
228	int ret;
229	ret = sscanf(buf, "%u", &input);
230
231	if (ret != 1)
232		return -EINVAL;
233
234	if (input > 100)
235		input = 100;
236
237	/*
238	 * no need to test here if freq_step is zero as the user might actually
239	 * want this, they would be crazy though :)
240	 */
241	cs_tuners->freq_step = input;
242	return count;
243}
244
245gov_show_one_common(sampling_rate);
246gov_show_one_common(sampling_down_factor);
247gov_show_one_common(up_threshold);
248gov_show_one_common(ignore_nice_load);
 
249gov_show_one(cs, down_threshold);
250gov_show_one(cs, freq_step);
251
252gov_attr_rw(sampling_rate);
253gov_attr_rw(sampling_down_factor);
254gov_attr_rw(up_threshold);
255gov_attr_rw(ignore_nice_load);
 
256gov_attr_rw(down_threshold);
257gov_attr_rw(freq_step);
258
259static struct attribute *cs_attrs[] = {
 
260	&sampling_rate.attr,
261	&sampling_down_factor.attr,
262	&up_threshold.attr,
263	&down_threshold.attr,
264	&ignore_nice_load.attr,
265	&freq_step.attr,
266	NULL
267};
268ATTRIBUTE_GROUPS(cs);
269
270/************************** sysfs end ************************/
271
272static struct policy_dbs_info *cs_alloc(void)
273{
274	struct cs_policy_dbs_info *dbs_info;
275
276	dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
277	return dbs_info ? &dbs_info->policy_dbs : NULL;
278}
279
280static void cs_free(struct policy_dbs_info *policy_dbs)
281{
282	kfree(to_dbs_info(policy_dbs));
283}
284
285static int cs_init(struct dbs_data *dbs_data)
286{
287	struct cs_dbs_tuners *tuners;
288
289	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
290	if (!tuners)
 
291		return -ENOMEM;
 
292
293	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
294	tuners->freq_step = DEF_FREQUENCY_STEP;
295	dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
296	dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
297	dbs_data->ignore_nice_load = 0;
 
298	dbs_data->tuners = tuners;
 
 
 
 
 
 
299
300	return 0;
301}
302
303static void cs_exit(struct dbs_data *dbs_data)
304{
 
 
 
 
305	kfree(dbs_data->tuners);
306}
307
308static void cs_start(struct cpufreq_policy *policy)
309{
310	struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
311
312	dbs_info->down_skip = 0;
313	dbs_info->requested_freq = policy->cur;
314}
315
316static struct dbs_governor cs_governor = {
317	.gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("conservative"),
318	.kobj_type = { .default_groups = cs_groups },
319	.gov_dbs_update = cs_dbs_update,
 
 
 
 
 
320	.alloc = cs_alloc,
321	.free = cs_free,
322	.init = cs_init,
323	.exit = cs_exit,
324	.start = cs_start,
325};
326
327#define CPU_FREQ_GOV_CONSERVATIVE	(cs_governor.gov)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
328
329MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
330MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
331		"Low Latency Frequency Transition capable processors "
332		"optimised for use in a battery environment");
333MODULE_LICENSE("GPL");
334
335#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
336struct cpufreq_governor *cpufreq_default_governor(void)
337{
338	return &CPU_FREQ_GOV_CONSERVATIVE;
339}
340#endif
341
342cpufreq_governor_init(CPU_FREQ_GOV_CONSERVATIVE);
343cpufreq_governor_exit(CPU_FREQ_GOV_CONSERVATIVE);
 
 
 
v4.6
 
  1/*
  2 *  drivers/cpufreq/cpufreq_conservative.c
  3 *
  4 *  Copyright (C)  2001 Russell King
  5 *            (C)  2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
  6 *                      Jun Nakajima <jun.nakajima@intel.com>
  7 *            (C)  2009 Alexander Clouter <alex@digriz.org.uk>
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License version 2 as
 11 * published by the Free Software Foundation.
 12 */
 13
 14#include <linux/slab.h>
 15#include "cpufreq_governor.h"
 16
 17struct cs_policy_dbs_info {
 18	struct policy_dbs_info policy_dbs;
 19	unsigned int down_skip;
 20	unsigned int requested_freq;
 21};
 22
 23static inline struct cs_policy_dbs_info *to_dbs_info(struct policy_dbs_info *policy_dbs)
 24{
 25	return container_of(policy_dbs, struct cs_policy_dbs_info, policy_dbs);
 26}
 27
 28struct cs_dbs_tuners {
 29	unsigned int down_threshold;
 30	unsigned int freq_step;
 31};
 32
 33/* Conservative governor macros */
 34#define DEF_FREQUENCY_UP_THRESHOLD		(80)
 35#define DEF_FREQUENCY_DOWN_THRESHOLD		(20)
 36#define DEF_FREQUENCY_STEP			(5)
 37#define DEF_SAMPLING_DOWN_FACTOR		(1)
 38#define MAX_SAMPLING_DOWN_FACTOR		(10)
 39
 40static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
 41					   struct cpufreq_policy *policy)
 42{
 43	unsigned int freq_target = (cs_tuners->freq_step * policy->max) / 100;
 44
 45	/* max freq cannot be less than 100. But who knows... */
 46	if (unlikely(freq_target == 0))
 47		freq_target = DEF_FREQUENCY_STEP;
 48
 49	return freq_target;
 50}
 51
 52/*
 53 * Every sampling_rate, we check, if current idle time is less than 20%
 54 * (default), then we try to increase frequency. Every sampling_rate *
 55 * sampling_down_factor, we check, if current idle time is more than 80%
 56 * (default), then we try to decrease frequency
 57 *
 58 * Any frequency increase takes it to the maximum frequency. Frequency reduction
 59 * happens at minimum steps of 5% (default) of maximum frequency
 60 */
 61static unsigned int cs_dbs_timer(struct cpufreq_policy *policy)
 62{
 63	struct policy_dbs_info *policy_dbs = policy->governor_data;
 64	struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
 
 65	struct dbs_data *dbs_data = policy_dbs->dbs_data;
 66	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
 67	unsigned int load = dbs_update(policy);
 
 68
 69	/*
 70	 * break out if we 'cannot' reduce the speed as the user might
 71	 * want freq_step to be zero
 72	 */
 73	if (cs_tuners->freq_step == 0)
 74		goto out;
 75
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 76	/* Check for frequency increase */
 77	if (load > dbs_data->up_threshold) {
 78		dbs_info->down_skip = 0;
 79
 80		/* if we are already at full speed then break out early */
 81		if (dbs_info->requested_freq == policy->max)
 82			goto out;
 83
 84		dbs_info->requested_freq += get_freq_target(cs_tuners, policy);
 85
 86		if (dbs_info->requested_freq > policy->max)
 87			dbs_info->requested_freq = policy->max;
 88
 89		__cpufreq_driver_target(policy, dbs_info->requested_freq,
 90			CPUFREQ_RELATION_H);
 91		goto out;
 92	}
 93
 94	/* if sampling_down_factor is active break out early */
 95	if (++dbs_info->down_skip < dbs_data->sampling_down_factor)
 96		goto out;
 97	dbs_info->down_skip = 0;
 98
 99	/* Check for frequency decrease */
100	if (load < cs_tuners->down_threshold) {
101		unsigned int freq_target;
102		/*
103		 * if we cannot reduce the frequency anymore, break out early
104		 */
105		if (policy->cur == policy->min)
106			goto out;
107
108		freq_target = get_freq_target(cs_tuners, policy);
109		if (dbs_info->requested_freq > freq_target)
110			dbs_info->requested_freq -= freq_target;
111		else
112			dbs_info->requested_freq = policy->min;
113
114		__cpufreq_driver_target(policy, dbs_info->requested_freq,
115				CPUFREQ_RELATION_L);
 
116	}
117
118 out:
119	return dbs_data->sampling_rate;
120}
121
122static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
123				void *data);
124
125static struct notifier_block cs_cpufreq_notifier_block = {
126	.notifier_call = dbs_cpufreq_notifier,
127};
128
129/************************** sysfs interface ************************/
130static struct dbs_governor cs_dbs_gov;
131
132static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
133		const char *buf, size_t count)
134{
 
135	unsigned int input;
136	int ret;
137	ret = sscanf(buf, "%u", &input);
138
139	if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
140		return -EINVAL;
141
142	dbs_data->sampling_down_factor = input;
143	return count;
144}
145
146static ssize_t store_up_threshold(struct dbs_data *dbs_data, const char *buf,
147		size_t count)
148{
 
149	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
150	unsigned int input;
151	int ret;
152	ret = sscanf(buf, "%u", &input);
153
154	if (ret != 1 || input > 100 || input <= cs_tuners->down_threshold)
155		return -EINVAL;
156
157	dbs_data->up_threshold = input;
158	return count;
159}
160
161static ssize_t store_down_threshold(struct dbs_data *dbs_data, const char *buf,
162		size_t count)
163{
 
164	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
165	unsigned int input;
166	int ret;
167	ret = sscanf(buf, "%u", &input);
168
169	/* cannot be lower than 11 otherwise freq will not fall */
170	if (ret != 1 || input < 11 || input > 100 ||
171			input >= dbs_data->up_threshold)
172		return -EINVAL;
173
174	cs_tuners->down_threshold = input;
175	return count;
176}
177
178static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data,
179		const char *buf, size_t count)
180{
 
181	unsigned int input;
182	int ret;
183
184	ret = sscanf(buf, "%u", &input);
185	if (ret != 1)
186		return -EINVAL;
187
188	if (input > 1)
189		input = 1;
190
191	if (input == dbs_data->ignore_nice_load) /* nothing to do */
192		return count;
193
194	dbs_data->ignore_nice_load = input;
195
196	/* we need to re-evaluate prev_cpu_idle */
197	gov_update_cpu_data(dbs_data);
198
199	return count;
200}
201
202static ssize_t store_freq_step(struct dbs_data *dbs_data, const char *buf,
203		size_t count)
204{
 
205	struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
206	unsigned int input;
207	int ret;
208	ret = sscanf(buf, "%u", &input);
209
210	if (ret != 1)
211		return -EINVAL;
212
213	if (input > 100)
214		input = 100;
215
216	/*
217	 * no need to test here if freq_step is zero as the user might actually
218	 * want this, they would be crazy though :)
219	 */
220	cs_tuners->freq_step = input;
221	return count;
222}
223
224gov_show_one_common(sampling_rate);
225gov_show_one_common(sampling_down_factor);
226gov_show_one_common(up_threshold);
227gov_show_one_common(ignore_nice_load);
228gov_show_one_common(min_sampling_rate);
229gov_show_one(cs, down_threshold);
230gov_show_one(cs, freq_step);
231
232gov_attr_rw(sampling_rate);
233gov_attr_rw(sampling_down_factor);
234gov_attr_rw(up_threshold);
235gov_attr_rw(ignore_nice_load);
236gov_attr_ro(min_sampling_rate);
237gov_attr_rw(down_threshold);
238gov_attr_rw(freq_step);
239
240static struct attribute *cs_attributes[] = {
241	&min_sampling_rate.attr,
242	&sampling_rate.attr,
243	&sampling_down_factor.attr,
244	&up_threshold.attr,
245	&down_threshold.attr,
246	&ignore_nice_load.attr,
247	&freq_step.attr,
248	NULL
249};
 
250
251/************************** sysfs end ************************/
252
253static struct policy_dbs_info *cs_alloc(void)
254{
255	struct cs_policy_dbs_info *dbs_info;
256
257	dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
258	return dbs_info ? &dbs_info->policy_dbs : NULL;
259}
260
261static void cs_free(struct policy_dbs_info *policy_dbs)
262{
263	kfree(to_dbs_info(policy_dbs));
264}
265
266static int cs_init(struct dbs_data *dbs_data, bool notify)
267{
268	struct cs_dbs_tuners *tuners;
269
270	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
271	if (!tuners) {
272		pr_err("%s: kzalloc failed\n", __func__);
273		return -ENOMEM;
274	}
275
276	tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
277	tuners->freq_step = DEF_FREQUENCY_STEP;
278	dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
279	dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
280	dbs_data->ignore_nice_load = 0;
281
282	dbs_data->tuners = tuners;
283	dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
284		jiffies_to_usecs(10);
285
286	if (notify)
287		cpufreq_register_notifier(&cs_cpufreq_notifier_block,
288					  CPUFREQ_TRANSITION_NOTIFIER);
289
290	return 0;
291}
292
293static void cs_exit(struct dbs_data *dbs_data, bool notify)
294{
295	if (notify)
296		cpufreq_unregister_notifier(&cs_cpufreq_notifier_block,
297					    CPUFREQ_TRANSITION_NOTIFIER);
298
299	kfree(dbs_data->tuners);
300}
301
302static void cs_start(struct cpufreq_policy *policy)
303{
304	struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
305
306	dbs_info->down_skip = 0;
307	dbs_info->requested_freq = policy->cur;
308}
309
310static struct dbs_governor cs_dbs_gov = {
311	.gov = {
312		.name = "conservative",
313		.governor = cpufreq_governor_dbs,
314		.max_transition_latency = TRANSITION_LATENCY_LIMIT,
315		.owner = THIS_MODULE,
316	},
317	.kobj_type = { .default_attrs = cs_attributes },
318	.gov_dbs_timer = cs_dbs_timer,
319	.alloc = cs_alloc,
320	.free = cs_free,
321	.init = cs_init,
322	.exit = cs_exit,
323	.start = cs_start,
324};
325
326#define CPU_FREQ_GOV_CONSERVATIVE	(&cs_dbs_gov.gov)
327
328static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
329				void *data)
330{
331	struct cpufreq_freqs *freq = data;
332	struct cpufreq_policy *policy = cpufreq_cpu_get_raw(freq->cpu);
333	struct cs_policy_dbs_info *dbs_info;
334
335	if (!policy)
336		return 0;
337
338	/* policy isn't governed by conservative governor */
339	if (policy->governor != CPU_FREQ_GOV_CONSERVATIVE)
340		return 0;
341
342	dbs_info = to_dbs_info(policy->governor_data);
343	/*
344	 * we only care if our internally tracked freq moves outside the 'valid'
345	 * ranges of frequency available to us otherwise we do not change it
346	*/
347	if (dbs_info->requested_freq > policy->max
348			|| dbs_info->requested_freq < policy->min)
349		dbs_info->requested_freq = freq->new;
350
351	return 0;
352}
353
354static int __init cpufreq_gov_dbs_init(void)
355{
356	return cpufreq_register_governor(CPU_FREQ_GOV_CONSERVATIVE);
357}
358
359static void __exit cpufreq_gov_dbs_exit(void)
360{
361	cpufreq_unregister_governor(CPU_FREQ_GOV_CONSERVATIVE);
362}
363
364MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
365MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
366		"Low Latency Frequency Transition capable processors "
367		"optimised for use in a battery environment");
368MODULE_LICENSE("GPL");
369
370#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
371struct cpufreq_governor *cpufreq_default_governor(void)
372{
373	return CPU_FREQ_GOV_CONSERVATIVE;
374}
 
375
376fs_initcall(cpufreq_gov_dbs_init);
377#else
378module_init(cpufreq_gov_dbs_init);
379#endif
380module_exit(cpufreq_gov_dbs_exit);