This solution worked for me.
1. First install acpi-call-tools
sudo apt-get install acpi-call-tools
2.
sudo modprobe -v acpi_call
3.
sudo echo “\_SB.PCI0.PEG0.GFX0.DOFF” > /proc/acpi/call
Note : I had to face permission denied when I did sudo as well. This quick fix solved that as well.
sudo chmod 777 /proc/acpi/call