** Changed in: linux (Ubuntu Mantic)
Status: In Progress => Fix Released
** Changed in: linux (Ubuntu Lunar)
Importance: Undecided => Medium
** Changed in: linux (Ubuntu Jammy)
Importance: Undecided => Medium
** Changed in: linux (Ubuntu Lunar)
Status: In Progress => Fix Committed
** Changed in: linux (Ubuntu Jammy)
Status: In Progress => Fix Committed
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https://bugs.launchpad.net/bugs/2030924
Title:
[SRU][Ubuntu 22.04.1] Unable to interpret the frequency values in
cpuinfo_min_freq and cpuino_max_freq sysfs files.
Status in linux package in Ubuntu:
Fix Released
Status in linux source package in Jammy:
Fix Committed
Status in linux source package in Lunar:
Fix Committed
Status in linux source package in Mantic:
Fix Released
Bug description:
[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 ]
This issue is seen on Intel based system under development which supports DBS
"Demand-Based Power Management", then install Ubuntu-22.04 and boot into OS then
check for the frequency values under /sys/devices/system/cpu/cpu0/cpufreq/cpu0
Regression risk = Low to medium
[ 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
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