Moved here as this is about LMDE and not about the main edition.
You would do an Internet search for that exact string you posted here, "[drm:ivybridge_irq_handler] *ERROR* Unclaimed register before interrupt". See if anybody else that has reported a problem that includes this message has something that matches up with your hardware. Try to focus on more recent messages. Anything older than 6 months is probably useless. Don't do a forum search--do an Internet search.
The error indicates a problem with your Ivy Bridge generation Intel CPU.
I've only spotted one other problem that seems to be related to yours: https://bugs.launchpad.net/ubuntu/+sour ... ug/1286192
. If you also have a Lenovo IdeaPad Flex 14 notebook, or close to it?
LMDE now has a new enough kernel that you should normally not expect any problems with Ivy Brigde generation Intel CPUs. But notebook manufacturers are know to make life complicated