Is there something in Linux that can report raw keycodes?
It's possible that a modifier might be stuck on. As in, if CTRL is stuck on, but there are other modifiers, sometimes ones that don't even have a key.
I'm pretty sure I've run something that can do this in Unix, but don't recall what it was. Possibly something that comes with X, so it may be present in Linux as well.
Also, an interrupt should be generated each time you press a key. If you can watch the interrupt counts in real time, that would tell you if you have keys that are dead in hardware. But again, I know how to do that in NetBSD, but specifically not in Linux.
It's possible that a modifier might be stuck on. As in, if CTRL is stuck on, but there are other modifiers, sometimes ones that don't even have a key.
I'm pretty sure I've run something that can do this in Unix, but don't recall what it was. Possibly something that comes with X, so it may be present in Linux as well.
Also, an interrupt should be generated each time you press a key. If you can watch the interrupt counts in real time, that would tell you if you have keys that are dead in hardware. But again, I know how to do that in NetBSD, but specifically not in Linux.