Few days ago I upgraded my laptop from ubuntu 17.10 to ubuntu 18.04. In my laptop it has two graphic controllers(intel and Nvidia). Normally I have been using
Nvidia X server tool for switching between them.
When I'm upgrading from 17.10 to 18.04 it was using
Nvidia graphics mode and not any of problems occurred during upgrade and successfully booted into ubuntu 18.04.
But my question is, after upgrade, I selected Intel graphics mode and now I can't boot my computer, because it is looping with an error message, where after the boot screen with ubuntu logo appears.
Note that I can't even log into tty sessions and fail safe graphics modes also didn't work.
So can anyone help me to resolve this error without reinstalling the entire operating system??