How to turn off Wireless power management permanently

Open this file with your favorite text editor, I use nano here:

sudo nano /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf

By default there is:

[connection]
wifi.powersave = 3

Change the value to 2. Reboot for the change to take effect.

---

Possible values for the wifi.powersave field are:

NM_SETTING_WIRELESS_POWERSAVE_DEFAULT (0): use the default value
NM_SETTING_WIRELESS_POWERSAVE_IGNORE  (1): don't touch existing setting
NM_SETTING_WIRELESS_POWERSAVE_DISABLE (2): disable powersave
NM_SETTING_WIRELESS_POWERSAVE_ENABLE  (3): enable powersave

(Informal source on GitHub for these values.)

It is not sufficient to turn off wireless power management at boot.

There are probably hooks like if I plug off power adapter.

So one of possible solutions is as follows; step-by-step.

Create a directory, where you wish to store the file, if not already having one for all your scripts, I personally want to have it in /etc/pm/:

sudo mkdir -p /etc/pm/power.d

Create (anywhere you like) a script, name it to be sensible, for me it is:

sudo nano /etc/pm/power.d/wireless_power_management_off

I used nano, but use whatever, e.g. if you want to create the file graphically, eg. with gedit (LM17) or xed (LM18):

gksudo gedit /etc/pm/power.d/wireless_power_management_off
gksudo xed /etc/pm/power.d/wireless_power_management_off

Enter the following contents to the file:

#!/bin/bash

/sbin/iwconfig wlan0 power off

Save the file.

Owner of the file should be root, if you created the file as normal user somewhere, go to the folder where it is and fix it with:

sudo chown root:root wireless_power_management_off

Next, you need to set proper permissions to the file, rwx for owner:

sudo chmod 700 wireless_power_management_off

Finally we will be executing the script every minute using CRON; dirty but worky:

sudo crontab -e

If you never edited crontab before, it will ask what editor you wish to use, this is totally up to you.

Paste this to the end of the file:

*/1 * * * * /etc/pm/power.d/wireless_power_management_off

Wait a minute and then you may check if power management if turned off:

iwconfig wlan0 | grep "Power Management"

Example output:

Power Management:off

Even if something triggers the power management to turn on, it will last only a minute. Done.

TLP - Linux Advanced Power Management Tool works for me out of the box with Ubuntu 18.04 and 20.04.

> grep WIFI /etc/default/tlp 
WIFI_PWR_ON_AC=off
WIFI_PWR_ON_BAT=off

> iw dev wlan0 get power_save
Power save: off

FWIW. Ansible role is available to configure TLP with Ubuntu.