This is very frustrating but the fix is usually easy once you read this blog. It's very frustrating when you find that your Linux / Ubuntu laptop's wifi will NEVER work unless it is plugged into the power. The wifi menu may say "Wifi disabled by hardware switch". You may find that your laptop has no switch or has a function wifi button on the keyboard but this does not work or have any effect.
The cause is usual a "wmi" kernel module and simply doing an rmmod / unloading this module will instantly allow your wifi to work.
Go to your terminal and type:
lsmod|grep wmi
If you see something like "acer_wmi"
type:
sudo rmmod acer_wmi
To make the fix permanent type this:
sudo vi /etc/modprobe.d/blacklist
#add a new line
blacklist acer_wmi
Of course be sure to replace acer_wmi with whatever your wmi is
Now you can finally enjoy true wireless wifi without having your laptop plugged into the AC power socket.
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