You may have noticed that even though the brightness icon is appearing on your screen, it’s not actually adjusting the brightness. Here’s how to fix it.

From command line, run the following:

sudo gedit /etc/default/grub

Add the following lines to the end of the file.

#For adjusting brightness on Yoga 13
acpi_blacklight=vendor

Save and close the file.

From terminal, run:

sudo update-grub

Finally, blacklist the other device:

sudo gedit /etc/modprobe.d/blacklist.conf

Add the following lines to the end of the file. Save and close it.

#For adjusting brightness on Yoga 13
blacklist ideapad_laptop

Now, save your work and reboot.