Touchpad not working on Ubuntu 20.04 and 21.04 - Lenovo Ideapad 5 ,ideapad 3 laptop fix

Open Termninal and follow steps.

sudo su

apt update

apt autoremove

apt upgrade

apt upgrade

apt install build-essentials -y

nano /etc/default/grub

(Edit “GRUB_CMDLINE_LINUX_DEFAULT to GRUB_CMDLINE_LINUX_DEFAULT= “quiet i8042.nopnp=1 pci=nocrs”)

update-grub

apt install git

git clone https://github.com/pavlepiramida/elan_i2c_dkms.git

apt install make dkms

cd elan_i2c_dkms

dkms install 

reboot