Frequency stuck at ~500 MHz after suspend->charge->unplug AC->resume on:
* HP EliteBook 6 G1ah 14 inch Notebook PC
* AMD Ryzen 5 220 w/ Radeon 740M Graphics
* Platform Firmware Information
Vendor: HP
Version: X77 Ver. 01.04.06
Release Date: 05/12/2026
* uname -a
Linux xe 7.1.3-arch1-2 #1 SMP PREEMPT_DYNAMIC Thu, 09 Jul 2026 x86_64 GNU/Linux
How to reproduce:
1) Start charging the laptop with lid closed
2) Detach laptop with lid *closed* from AC power
3) Open the lid. Then frequenccies on most cores remain stuck *low*:
# >> Cat files in /sys/devices/system/cpu/cpu*/cpufreq | sort-ed | uniq-
ued:
/sys/devices/system/cpu/cpu0/cpufreq/scaling_driver: amd-pstate-epp
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: powersave
/sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference:
balance_power
# grep cpu.MHz /proc/cpuinfo | cut -d: -f2| nl -v 0
0 544.363
1 544.358
2 520.431
3 519.626
4 520.400
5 1117.810
6 520.059
7 520.041
8 544.355
9 1117.810
10 520.488
11 1117.810
4) Attach AC-power for 5 sec when the lid is *open*
5) Detach AC-power leaving the *lid open*. The cpu-frequencies 'wake up':
# >> Cat files in /sys/devices/system/cpu/cpu*/cpufreq | sort-ed | uniq-ued:
/sys/devices/system/cpu/cpu0/cpufreq/scaling_driver: amd-pstate-epp
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: powersave
/sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference:
balance_power
# grep cpu.MHz /proc/cpuinfo | cut -d: -f2| nl -v 0
0 1365.791
1 1367.646
2 2278.527
3 1117.810
4 2278.704
5 1117.810
6 1364.481
7 1366.707
8 2152.118
9 1437.688
10 2275.372
11 2277.464
6) Further repeated flipping the lid and re-opening when run on BAT0
retain the normal frequencies.
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https://bugs.launchpad.net/bugs/2088733
Title:
low CPU frequency after wake up AMD Ryzen
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