I am getting a similar issue with Ubuntu 14.04 and kernel 3.19.0-31 on Lenovo T440p. The system freezes at login screen and can't be used after that only thing that can be done is a hard reset.
Works OK on the other hand with 3.19.0-30.
Linux weaz-K8 3.19.0-30-generic #34~14.04.1-Ubuntu SMP Fri Oct 2 22:09:39 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
I am getting a similar issue with Ubuntu 14.04 and kernel 3.19.0-31 on Lenovo T440p. The system freezes at login screen and can't be used after that only thing that can be done is a hard reset.
Works OK on the other hand with 3.19.0-30.
Linux weaz-K8 3.19.0-30-generic #34~14.04.1-Ubuntu SMP Fri Oct 2 22:09:39 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux