If I restore my system from being suspended to RAM while I don't have an AC adapter plugged-in, the CPU scaling is locked at the lowest value, and I'm unable to change it. It's unlocked as soon as I plug in an AC-adapter.
I wonder if this is a feature of my machine (Dell Latitude 3550) or is it an OS thing.
This frequently makes my system useless when working mobile, as my work requires high CPU speed. This didn't seem to be an issue until recently.
Sorry if I should post this somewhere else, please direct me if you can.
CPU frequency locked at min. after unsuspening on battery
Moderators: MattKingUSA, khz
Re: CPU frequency locked at min. after unsuspening on batter
What cpu governor is working in your system?
Can you post output of this command:
I have used this command to change cpu governor to performance:
The best forum to address this issue is your linux distro forum .
I think it's a broken acpi in dell....
Can you post output of this command:
Code: Select all
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
Code: Select all
echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
I think it's a broken acpi in dell....
- unfa
- Established Member
- Posts: 129
- Joined: Tue May 17, 2011 10:43 am
- Location: Warsaw, Poland
- Has thanked: 1 time
- Been thanked: 19 times
- Contact:
Re: CPU frequency locked at min. after unsuspening on batter
Now I tried, and the phenomenon happens every time I disconnect the AC adapter.
When I plug it back in the CPU gets performance back.
However the CPU governor is reported to be ondemand all the time.
When I plug it back in the CPU gets performance back.
However the CPU governor is reported to be ondemand all the time.
Last edited by unfa on Thu Aug 20, 2015 7:15 pm, edited 1 time in total.
Re: CPU frequency locked at min. after unsuspening on batter
Try to change to performace governor with this command:
Is it working?
Is this command showing errors?
Code: Select all
echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
Is this command showing errors?
Code: Select all
dmesg
- unfa
- Established Member
- Posts: 129
- Joined: Tue May 17, 2011 10:43 am
- Location: Warsaw, Poland
- Has thanked: 1 time
- Been thanked: 19 times
- Contact:
Re: CPU frequency locked at min. after unsuspening on batter
The governer is being changed fine, but he CPU frequency is unaffected.
dmesg doesn't report any errors. I found something, but it doesn't show up when I plug/unplug the AC adapter, so I think it's not related:
dmesg doesn't report any errors. I found something, but it doesn't show up when I plug/unplug the AC adapter, so I think it's not related:
Code: Select all
[36395.298210] NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter.
Re: CPU frequency locked at min. after unsuspening on batter
one more idea:unfa wrote:The governer is being changed fine, but he CPU frequency is unaffected.
try this to see what is cpu max freq on your system:
Code: Select all
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
Code: Select all
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
Code: Select all
echo MAXFREQNUMBER | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq