Hi, any idea why CPU frequency scaling doesn't work for 3.14.25-rt22 [1] and why it does work for 3.17.6 [2]? Regards, Ralf [1] [rocketmouse@archlinux ~]$ uname -rm 3.14.25-rt22-1-rt x86_64 [rocketmouse@archlinux ~]$ zgrep CONFIG_CPU_FREQ /proc/config.gz CONFIG_CPU_FREQ=y CONFIG_CPU_FREQ_GOV_COMMON=y CONFIG_CPU_FREQ_STAT=m CONFIG_CPU_FREQ_STAT_DETAILS=y CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y # CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set # CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set # CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set CONFIG_CPU_FREQ_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_POWERSAVE=m CONFIG_CPU_FREQ_GOV_USERSPACE=m CONFIG_CPU_FREQ_GOV_ONDEMAND=y CONFIG_CPU_FREQ_GOV_CONSERVATIVE=m [rocketmouse@archlinux ~]$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor performance performance [rocketmouse@archlinux ~]$ echo ondemand | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor [sudo] password for rocketmouse: ondemand tee: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: Invalid argument [rocketmouse@archlinux ~]$ [2] [rocketmouse@archlinux ~]$ uname -rm 3.17.6-1-ARCH x86_64 [rocketmouse@archlinux ~]$ zgrep CONFIG_CPU_FREQ /proc/config.gz CONFIG_CPU_FREQ=y CONFIG_CPU_FREQ_GOV_COMMON=y CONFIG_CPU_FREQ_STAT=m CONFIG_CPU_FREQ_STAT_DETAILS=y # CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE is not set # CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y # CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set CONFIG_CPU_FREQ_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_POWERSAVE=m CONFIG_CPU_FREQ_GOV_USERSPACE=m CONFIG_CPU_FREQ_GOV_ONDEMAND=y CONFIG_CPU_FREQ_GOV_CONSERVATIVE=m [rocketmouse@archlinux ~]$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ondemand ondemand [rocketmouse@archlinux ~]$ echo performance | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor [sudo] password for rocketmouse: performance [rocketmouse@archlinux ~]$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor performance performance [rocketmouse@archlinux ~]$ echo ondemand | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor ondemand [rocketmouse@archlinux ~]$ cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor ondemand ondemand [rocketmouse@archlinux ~]$