Upgrade – Laptop Can’t Control Fan Speed After Ubuntu 16.04 Upgrade

I had to install the proprietary Nvidia driver. Start the "Additional Drivers" program and install it from there. Reboot and the fan starts operating on normal speed.

The drivers I downloaded myself from Nvidia website didn't work.

I'm pretty sure @wjandrea suggested this in comments, but he says he didn't. I'd still like to give him the credit for solving this!

I found a solution for my Vostro 5481. It might work for you (and others) as well.

Required

git clone https://github.com/TomFreudenberg/dell-bios-fan-control.git
cd dell-bios-fan-control
make
sudo ./dell-bios-fan-control 0

If you get an error like this

ioperm:: Operation not permitted 
ioperm:: Operation not permitted [1] 
4701 segmentation fault

you need to go to your BIOS/UEFI and disable SECURE BOOT. Then run the command again. Output should now be BIOS CONTROL DISABLED.

Quick testing
You can now go and check solutions for controlling the fan that suite your needs. If you want to quickly test, you can use i8kutils:

git clone https://github.com/vitorafsr/i8kutils
cd i8kutils
make
sudo ./i8kctl fan 2 2

Your fan should now run at the highest possible settings without the BIOS/UEFI interfering.

Controlling the fan in day to day business
Now that your BIOS/UEFI is no longer controlling the fan, you have to take care of it on your own. I'd suggest https://linux.die.net/man/8/fancontrol for this. It can easily be configured using pwmonfig (which ships with it) and adds itself as a system service.

Big THANKS
Shoutout to Tom Freudenberg for creating dell-bios-fan-control and for pointing me to disabling SECURE_BOOT when I got the Operation not permitted error.

https://github.com/TomFreudenberg
https://askubuntu.com/users/293845/tom-freudenberg.