prevent divide by zero after suspended screens
On a Lenovo t430, dock, using displayport and 2 4K external screens a divide crash happens after waking up the screens (and chose different input) . this fix prevents :
- screen(s) lockup
- high system load after above issue triggered (50+ has been observed)
- hangs during reboot (after issue was triggered)
and make the system usable, so it recovers. The actual root-cause is unknown to me, pretty new to nouveau driver itself.
Looks like all (recent) kernels might need this, or similar fix. (started to look at this using ubuntu stock kernel v6.8.0)
Note: this merge request is to prevent the crash, but likely not solve the real problem/edge case. Feel free to modify, just take the idea and implement it your way.