From 6afde10c3f58cc3ac593f5b4505b8b1cf719f5d6 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Tue, 2 Oct 2007 13:28:13 -0700 Subject: [PATCH] [CPUFREQ] Only check for transition latency on problematic governors (kconfig fix) Cc: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq.c | 27 ++++++++++++++++++++------- include/linux/cpufreq.h | 3 ++- 2 files changed, 22 insertions(+), 8 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 418522f88f73..65ac58511228 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1484,17 +1484,30 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event) { int ret; - struct cpufreq_governor *gov = CPUFREQ_PERFORMANCE_GOVERNOR; + + /* Only must be defined when default governor is known to have latency + restrictions, like e.g. conservative or ondemand. + That this is the case is already ensured in Kconfig + */ +#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE + struct cpufreq_governor *gov = &cpufreq_gov_performance; +#else + struct cpufreq_governor *gov = NULL; +#endif 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 (!gov) + return -EINVAL; + else { + 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)) diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 9e5f5d0c87f3..450a841b5892 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -286,8 +286,9 @@ static inline unsigned int cpufreq_quick_get(unsigned int cpu) Performance governor is fallback governor if any other gov failed to auto load due latency restrictions */ +#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE extern struct cpufreq_governor cpufreq_gov_performance; -#define CPUFREQ_PERFORMANCE_GOVERNOR (&cpufreq_gov_performance) +#endif #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE #define CPUFREQ_DEFAULT_GOVERNOR (&cpufreq_gov_performance) #elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE) -- 2.20.1