diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig index 993fa7b89253..721f86f4f008 100644 --- a/drivers/cpufreq/Kconfig +++ b/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/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 9528bd577365..418522f88f73 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/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/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index 26f440ccc3fb..4bd33ce8a6f3 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/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; @@ -551,15 +548,17 @@ 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) @@ -567,7 +566,7 @@ 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/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index e794527e4925..369f44595150 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/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/include/linux/cpufreq.h b/include/linux/cpufreq.h index 3ec6e7ff5fbd..9e5f5d0c87f3 100644 --- a/include/linux/cpufreq.h +++ b/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