---

yaml --- r: 67783 b: refs/heads/master c: 1c25624 h: refs/heads/master i: 67781: d591555 67779: 44552c4 67775: f3ac1c9 v: v3
git-mirror · Oct 4, 2007 · e3fbe00 · e3fbe00
1 parent 562d8ac
commit e3fbe00
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Showing 6 changed files with 71 additions and 31 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8122c6cea033e8034e99d3b10a4e3f377ce23994
+refs/heads/master: 1c2562459faedc35927546cfa5273ec6c2884cce
diff --git a/trunk/drivers/cpufreq/Kconfig b/trunk/drivers/cpufreq/Kconfig
@@ -56,10 +56,6 @@ config CPU_FREQ_STAT_DETAILS
 
 	  If in doubt, say N.
 
-# Note that it is not currently possible to set the other governors (such as ondemand)
-# as the default, since if they fail to initialise, cpufreq will be
-# left in an undefined state.
-
 choice
 	prompt "Default CPUFreq governor"
 	default CPU_FREQ_DEFAULT_GOV_USERSPACE if CPU_FREQ_SA1100 || CPU_FREQ_SA1110
@@ -85,6 +81,29 @@ config CPU_FREQ_DEFAULT_GOV_USERSPACE
 	  program shall be able to set the CPU dynamically without having
 	  to enable the userspace governor manually.
 
+config CPU_FREQ_DEFAULT_GOV_ONDEMAND
+	bool "ondemand"
+	select CPU_FREQ_GOV_ONDEMAND
+	select CPU_FREQ_GOV_PERFORMANCE
+	help
+	  Use the CPUFreq governor 'ondemand' as default. This allows
+	  you to get a full dynamic frequency capable system by simply
+	  loading your cpufreq low-level hardware driver.
+	  Be aware that not all cpufreq drivers support the ondemand
+	  governor. If unsure have a look at the help section of the
+	  driver. Fallback governor will be the performance governor.
+
+config CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
+	bool "conservative"
+	select CPU_FREQ_GOV_CONSERVATIVE
+	select CPU_FREQ_GOV_PERFORMANCE
+	help
+	  Use the CPUFreq governor 'conservative' as default. This allows
+	  you to get a full dynamic frequency capable system by simply
+	  loading your cpufreq low-level hardware driver.
+	  Be aware that not all cpufreq drivers support the conservative
+	  governor. If unsure have a look at the help section of the
+	  driver. Fallback governor will be the performance governor.
 endchoice
 
 config CPU_FREQ_GOV_PERFORMANCE

diff --git a/trunk/drivers/cpufreq/cpufreq.c b/trunk/drivers/cpufreq/cpufreq.c
@@ -1484,6 +1484,18 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
 					unsigned int event)
 {
 	int ret;
+	struct cpufreq_governor *gov = CPUFREQ_PERFORMANCE_GOVERNOR;
+
+	if (policy->governor->max_transition_latency &&
+	    policy->cpuinfo.transition_latency >
+	    policy->governor->max_transition_latency) {
+		printk(KERN_WARNING "%s governor failed, too long"
+		       " transition latency of HW, fallback"
+		       " to %s governor\n",
+		       policy->governor->name,
+		       gov->name);
+		       policy->governor = gov;
+	}
 
 	if (!try_module_get(policy->governor->owner))
 		return -EINVAL;

diff --git a/trunk/drivers/cpufreq/cpufreq_conservative.c b/trunk/drivers/cpufreq/cpufreq_conservative.c
@@ -58,7 +58,7 @@ static unsigned int 				def_sampling_rate;
 #define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER	(1000)
 #define DEF_SAMPLING_DOWN_FACTOR		(1)
 #define MAX_SAMPLING_DOWN_FACTOR		(10)
-#define TRANSITION_LATENCY_LIMIT		(10 * 1000)
+#define TRANSITION_LATENCY_LIMIT		(10 * 1000 * 1000)
 
 static void do_dbs_timer(struct work_struct *work);
 
@@ -466,9 +466,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		    (!policy->cur))
 			return -EINVAL;
 
-		if (policy->cpuinfo.transition_latency >
-				(TRANSITION_LATENCY_LIMIT * 1000))
-			return -EINVAL;
 		if (this_dbs_info->enable) /* Already enabled */
 			break;
 
@@ -551,23 +548,25 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 	return 0;
 }
 
-static struct cpufreq_governor cpufreq_gov_dbs = {
-	.name		= "conservative",
-	.governor	= cpufreq_governor_dbs,
-	.owner		= THIS_MODULE,
+struct cpufreq_governor cpufreq_gov_conservative = {
+	.name			= "conservative",
+	.governor		= cpufreq_governor_dbs,
+	.max_transition_latency	= TRANSITION_LATENCY_LIMIT,
+	.owner			= THIS_MODULE,
 };
+EXPORT_SYMBOL(cpufreq_gov_conservative);
 
 static int __init cpufreq_gov_dbs_init(void)
 {
-	return cpufreq_register_governor(&cpufreq_gov_dbs);
+	return cpufreq_register_governor(&cpufreq_gov_conservative);
 }
 
 static void __exit cpufreq_gov_dbs_exit(void)
 {
 	/* Make sure that the scheduled work is indeed not running */
 	flush_scheduled_work();
 
-	cpufreq_unregister_governor(&cpufreq_gov_dbs);
+	cpufreq_unregister_governor(&cpufreq_gov_conservative);
 }
 
 

diff --git a/trunk/drivers/cpufreq/cpufreq_ondemand.c b/trunk/drivers/cpufreq/cpufreq_ondemand.c
@@ -47,7 +47,7 @@ static unsigned int def_sampling_rate;
 			(def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
 #define MAX_SAMPLING_RATE			(500 * def_sampling_rate)
 #define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER	(1000)
-#define TRANSITION_LATENCY_LIMIT		(10 * 1000)
+#define TRANSITION_LATENCY_LIMIT		(10 * 1000 * 1000)
 
 static void do_dbs_timer(struct work_struct *work);
 
@@ -508,12 +508,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 		if ((!cpu_online(cpu)) || (!policy->cur))
 			return -EINVAL;
 
-		if (policy->cpuinfo.transition_latency >
-				(TRANSITION_LATENCY_LIMIT * 1000)) {
-			printk(KERN_WARNING "ondemand governor failed to load "
-			       "due to too long transition latency\n");
-			return -EINVAL;
-		}
 		if (this_dbs_info->enable) /* Already enabled */
 			break;
 
@@ -585,11 +579,13 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 	return 0;
 }
 
-static struct cpufreq_governor cpufreq_gov_dbs = {
-	.name = "ondemand",
-	.governor = cpufreq_governor_dbs,
-	.owner = THIS_MODULE,
+struct cpufreq_governor cpufreq_gov_ondemand = {
+	.name			= "ondemand",
+	.governor		= cpufreq_governor_dbs,
+	.max_transition_latency = TRANSITION_LATENCY_LIMIT,
+	.owner			= THIS_MODULE,
 };
+EXPORT_SYMBOL(cpufreq_gov_ondemand);
 
 static int __init cpufreq_gov_dbs_init(void)
 {
@@ -598,12 +594,12 @@ static int __init cpufreq_gov_dbs_init(void)
 		printk(KERN_ERR "Creation of kondemand failed\n");
 		return -EFAULT;
 	}
-	return cpufreq_register_governor(&cpufreq_gov_dbs);
+	return cpufreq_register_governor(&cpufreq_gov_ondemand);
 }
 
 static void __exit cpufreq_gov_dbs_exit(void)
 {
-	cpufreq_unregister_governor(&cpufreq_gov_dbs);
+	cpufreq_unregister_governor(&cpufreq_gov_ondemand);
 	destroy_workqueue(kondemand_wq);
 }
 

diff --git a/trunk/include/linux/cpufreq.h b/trunk/include/linux/cpufreq.h
@@ -155,6 +155,9 @@ struct cpufreq_governor {
 	char	name[CPUFREQ_NAME_LEN];
 	int 	(*governor)	(struct cpufreq_policy *policy,
 				 unsigned int event);
+	unsigned int max_transition_latency; /* HW must be able to switch to
+			next freq faster than this value in nano secs or we
+			will fallback to performance governor */
 	struct list_head	governor_list;
 	struct module		*owner;
 };
@@ -279,12 +282,23 @@ static inline unsigned int cpufreq_quick_get(unsigned int cpu)
  *********************************************************************/
 
 
-#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
+/*
+  Performance governor is fallback governor if any other gov failed to
+  auto load due latency restrictions
+*/
 extern struct cpufreq_governor cpufreq_gov_performance;
-#define CPUFREQ_DEFAULT_GOVERNOR	&cpufreq_gov_performance
+#define CPUFREQ_PERFORMANCE_GOVERNOR	(&cpufreq_gov_performance)
+#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
+#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_performance)
 #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
 extern struct cpufreq_governor cpufreq_gov_userspace;
-#define CPUFREQ_DEFAULT_GOVERNOR	&cpufreq_gov_userspace
+#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_userspace)
+#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
+extern struct cpufreq_governor cpufreq_gov_ondemand;
+#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_ondemand)
+#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
+extern struct cpufreq_governor cpufreq_gov_conservative;
+#define CPUFREQ_DEFAULT_GOVERNOR	(&cpufreq_gov_conservative)
 #endif