Comment 29 for bug 1188647

I'm posting here because pstate is giving me problems as well, but in the opposite direction. Upon bootup and for several hours thereafter, scaling works correctly. But after a period of time something happens (which is of course not mentioned in any log) and scaling_max_freq is set to scaling_min_freq and cannot be changed at all.

root@ossy:/etc# cd /sys/devices/system/cpu/cpu0/cpufreq
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# ls
affected_cpus cpuinfo_transition_latency scaling_driver scaling_setspeed
cpuinfo_cur_freq related_cpus scaling_governor
cpuinfo_max_freq scaling_available_governors scaling_max_freq
cpuinfo_min_freq scaling_cur_freq scaling_min_freq
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# cat scaling_max_freq
1600000
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# cat cpuinfo_max_freq
3700000
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# cat cpuinfo_max_freq > scaling_max_freq
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# cat scaling_max_freq
1600000

root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# echo performance > scaling_governor
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# cat scaling_governor
performance
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# cat cpuinfo_max_freq > scaling_max_freq
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# cat scaling_max_freq
1600000

This happens whether or not I have Enhanced SpeedStep enabled in my BIOS. (This is also not a BIOS limit problem.) Disabling pstate entirely allows me to run at 3.3GHz all the time. Since powerclamp is loaded and thermald is running I'm still protected from overheating situations. Since this is a desktop I don't really care about the power usage but I can see where this would be a bigger problem for laptops.