Comment 0 for bug 2030924

[Impact]

On DELL EMC PowerEdge system when Ubuntu 22.04.1 OS is Installed, Unable to Interpret the values in cpuinfo_max_freq and cpuinfo_min_freq sysfs files as per the Intel specs document.

Steps to Reproduce:

1. Install one CPU that supports DBS "Demand-Based Power Management".
2. Install Ubuntu 22.04.1 OS.
2. Enable "Logical Processor" under CPU Information menu from F2 setup.
3. Save changes and reboot to Ubuntu 22.04.1 OS.
4. Right click on "Computer" and select "File system" and check for the following CPU directories.

   /sys/devices/system/cpu/cpu0/cpufreq/cpu0
   /sys/devices/system/cpu/cpu0/cpufreq/cpu1

5. View the Max Frequency and Min Frequency under CPU0 and CPU1 directory.
6. The Max and Min Frequency did not match as per the Intel specs datasheet.

Actual results:

 /sys/devices/system/cpu/cpu0/cpufreq/cpu0/cpuinfo_max_freq -> 6800000
 /sys/devices/system/cpu/cpu0/cpufreq/cpu0/cpuinfo_min_freq -> 800000
 /sys/devices/system/cpu/cpu0/cpufreq/cpu0/base_frequency -> 3900000

 Expected results: As per Intel datasheet specification.

 /sys/devices/system/cpu/cpu0/cpufreq/cpu0/cpuinfo_max_freq -> 5300 MHz
 /sys/devices/system/cpu/cpu0/cpufreq/cpu0/cpuinfo_min_freq -> 800 MHz
 /sys/devices/system/cpu/cpu0/cpufreq/cpu0/base_frequency -> 3000 MHz

[Fix]
cpufreq: intel_pstate: Fix scaling for hybrid-capable systems with disabled E-cores
https://github.com/torvalds/linux/commit/0fcfc9e51990246a9813475716746ff5eb98c6aa [github.com]

[Test Plan]

Same as steps to reproduce

[ Where problems could occur ]

[ Other Info ]

Jammy
https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/jammy/+ref/cpuinfo_freq

lunar
https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/lunar/+ref/cpuinfo_freq_lunar_2

Mantic
https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/mantic/+ref/cpuinfo_freq_mantic