Not readable 'scaling_governor'

Hi,

in the latest Linus's kernel this file is not readable:

$ cat /sys/devices/system/cpu/cpu91/cpufreq/scaling_governor 
cat: /sys/devices/system/cpu/cpu91/cpufreq/scaling_governor: Invalid argument

I did not try to bisect, and it must be bug. Known issue?

I checked this commit: ca7e1fd1026c

Thanks,
Artem.