I installed ubuntu 16.04 on my T440s and upgraded it to most recent version (kernel and software).
After this I noticed to major issues : - random freeze with "general protection fault" in logs when waking up from hibernate (a.k.a suspend to disk).
the hibernation step itself ends well, but the waking up ends half times with a black screen and totally unresponsive system. Note
that it can actually resume well at some times.
- HDMI screen is no more detected, absolutely nothing happens in logs or whatosever when I plug the cable.
Before, with ubuntu 14.04, both HDMI and hibernation used to work well. Very rarely, the hibernation wakeup could fail, but not so often, all I had to do is to add the wifi module in SUSPEND_MODULES list.
I googled both issues, tried other kernels (4.4.9, 4.6), other suspend tools (uswup), other graphic nvidia drivers. Nor HDMI neither stable hibernation.
For HDMI, I do not suspect the cable (displayport to hdmi) as it was working well before installing ubuntu 16.04. If it was damaged, probably I could not use the remote screen, but at least it would detect some kind of connection.
Between 14.04 and 16 .04, the only noticeable change in the setup is that I installed everything on an encrypted (dm-crypt, luks) partition, which is split into several logical (LVM) volumes (swap, root "/", and home).
I would very much appreciate if you could help me in solving these bugs which greatly limit my laptop usage.
Thanks in advance for your attention.
PS : this mail has been sent twice due to a bug between the chair and the keyboard, sorry.