Comment 32 for bug 1188647

Wow. I've never seen this before. My scaling_min_freq and scaling_max_freq are now set to... 0!

root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# ls -1 *
affected_cpus
cpuinfo_cur_freq
cpuinfo_max_freq
cpuinfo_min_freq
cpuinfo_transition_latency
related_cpus
scaling_available_governors
scaling_cur_freq
scaling_driver
scaling_governor
scaling_max_freq
scaling_min_freq
scaling_setspeed
root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# cat *
0
1737414
3700000
1600000
4294967295
0
performance powersave
1737414
intel_pstate
performance
0
0
<unsupported>

root@ossy:/sys/devices/system/cpu/cpu0/cpufreq# uname -a
Linux ossy 4.10.0-041000rc6-generic #201701291830 SMP Sun Jan 29 23:32:29 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

And now scaling_max_freq is stuck:

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
0

Inside of the intel_pstate folder, I can move max_perf_pct up to 44 max, and turn on turbo:

root@ossy:/sys/devices/system/cpu/intel_pstate# ls -1
max_perf_pct
min_perf_pct
no_turbo
num_pstates
turbo_pct
root@ossy:/sys/devices/system/cpu/intel_pstate# cat *
0
0
1
22
19
root@ossy:/sys/devices/system/cpu/intel_pstate# echo 40 > min_perf_pct
root@ossy:/sys/devices/system/cpu/intel_pstate# cat min_perf_pct
0
root@ossy:/sys/devices/system/cpu/intel_pstate# echo 100 > max_perf_pct
root@ossy:/sys/devices/system/cpu/intel_pstate# cat max_perf_pct
44
root@ossy:/sys/devices/system/cpu/intel_pstate# echo 0 > no_turbo
root@ossy:/sys/devices/system/cpu/intel_pstate# cat no_turbo
0
root@ossy:/sys/devices/system/cpu/intel_pstate# echo 100 > max_perf_pct
root@ossy:/sys/devices/system/cpu/intel_pstate# cat max_perf_pct
44

But I'm sure at some point later it will go down again and not go back up until I change things manually (or reboot). Not entirely sure when this happened. I had it running for over 12 hours (including a lot of load with BOINC projects overnight). It wasn't stuck like this in the morning, but at some point today it got into this state. Nothing strange I can see in my system log, except for maybe

[13347.141990] powercap intel-rapl:0: package locked by BIOS, monitoring only

But I don't think my BIOS is limiting anything because when I
echo 1 > /sys/module/processor/parameters/ignore_ppc
it doesn't make a difference, I still can't change any of the values (scaling_max_freq or max_perf_pct) that I want to get my original speed back, only rebooting helps.

Anyway, if you don't think this is the right bug I can open another one or something, but unless you can suggest a patch to try or a setting to change I am probably just going to disable pstate on the GRUB command line and be done with it (and of course ensure thermald and powerclamp are running and my fans are in good shape and as dust-free as can be).