Ok. So I have Bumblebee and bbswitch installed. When I did *cat /proc/acpi/bbswitch* I could see that it was OFF.

However, when I tried to do
sudo lspci -nnk | grep -A3 VGA
in the terminal to determine which card I was using, it completely hanged there. The computer just froze. I had to force shutdown by pressing the power button.

Any ideas on how is this possible? I mean, really, I did not do anything else other than a line of command to check my graphic cards. Or it's just I should not use this command because I have bumblebee installed (although I don't think so)? Lately I've seen too many graphic cards related bugs and issues for kernel 4.14 and it really upset me...

Thank you.