Power management

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Revision as of 14:58, 26 June 2013 by Lahwaacz (talk | contribs) (Kernel Command Line Parameters: deduplication)
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The aim of this page is to try to gather all the informations which are available on the topic of linux power management features. There are several places where one can change power management settings:

Power settings you set in one place could be overwritten in another place.

Power saving

See power saving.

Where To Change Power Settings

One can pass a kernel command line parameter in the boot loader to activate power management features in certain kernel modules. If you are using systemd you can change some power management options in systemd config files or execute your own config file. pm-utils and upower work together. pm-utils is responsible for changing the power management options while upower informs pm-utils about system changes. For example, if you unplug your laptop from AC power then upower will signal to pm-utils that the laptop is running on battery. This will cause pm-utils to change some power management options according to its config files.

Have a look at the power management category to get an overview on what power management options exists in Archlinux:.

Kernel Command Line Parameters

See Kernel modules#Using kernel command line for more information.

Enable RC6 Power Save Options


Where #Nr:

  • 1: enable rc6
  • 3: enable rc6 and deep rc6
  • 5: enable rc6 and deepest rc6
  • 7: enable rc6, deep and deepest rc6


Connection problems with Atheros AR9485 Wireless Network Adapter

You may experience connection problems with the Atheros AR9485 Wireless Network Adapter, which is caused by incorrect power management functioning. You can notice the problem if you're experiencing random disconnections in IM or other software that keeps connection alive for a long time. In case you're using laptop, first you must disable battery power-over-perfomance feature: Settings / Power Manager / On Battery / Prefer power savings over perfomance

Next thing to do is switch off power management for adapter: You should add

iwconfig wlan0 power off

(assuming wlan0 is your AR9485 adapter) anywhere it can be executed on system init (or simply run it once, to fix the problem for current session) and that should do it.

See Also

CPU Frequency Scaling