diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.h')
| -rw-r--r-- | drivers/cpufreq/cpufreq_ondemand.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.h b/drivers/cpufreq/cpufreq_ondemand.h index 1af8e5c4b86f..2ca8f1aaf2e3 100644 --- a/drivers/cpufreq/cpufreq_ondemand.h +++ b/drivers/cpufreq/cpufreq_ondemand.h @@ -24,3 +24,26 @@ static inline struct od_policy_dbs_info *to_dbs_info(struct policy_dbs_info *pol struct od_dbs_tuners { unsigned int powersave_bias; }; + +#ifdef CONFIG_X86 +#include <asm/cpu_device_id.h> + +/* + * Not all CPUs want IO time to be accounted as busy; this depends on + * how efficient idling at a higher frequency/voltage is. + * + * Pavel Machek says this is not so for various generations of AMD and + * old Intel systems. Mike Chan (android.com) claims this is also not + * true for ARM. + * + * Because of this, select a known series of Intel CPUs (Family 6 and + * later) by default, and leave all others up to the user. + */ +static inline bool od_should_io_be_busy(void) +{ + return (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86_vfm >= INTEL_PENTIUM_PRO); +} +#else +static inline bool od_should_io_be_busy(void) { return false; } +#endif |