I recently restarted after an update on 15.10, and now the keyboard on my laptop (Lenovo Thinkpad Yoga) doesn't work. I can't even ctrl-alt-[N] to get to a virtual terminal, nor does a USB keyboard work. The keyboard does work in BIOS setup and GRUB mode, but that's it. Also, the touchscreen stopped working at the same time. I had also changed a line in a xorg.conf.d file, affecting the synaptics driver prior to this, but I can't work out why this would kill the keyboard and touchscreen.
2 Answers
OK; looks like the xorg.conf.d file was the problem; I dropped into a recovery boot and reverted that file. When it had the line Driver "synaptics"
under InputClass the keyboard no longer worked. Reverting this to MatchDriver
that was there previously (And I think is in error) meant I've got keyboard again.
In my ubuntu 14.04 keyboard was working up to the grub menu, after that it stopped responding. apart from this, my network also not working.
So, I have restarted ubuntu in recovery mode and selected a different kernel. Now both keyboard and network start working.
What I understood from this is - my latest kernel failed to load these modules.