Comment 160 for bug 1566302

Hi, I have same problem and probably my bug report will help to find the problem.

Currently I'm using Lenovo Thinkpad Carbon 4th gen and ubuntu 16.04.2:
Linux carbon 4.8.0-54-generic #57~16.04.1-Ubuntu SMP Wed May 24 16:22:28 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

I have problems with suspend only after I plug external screen to my computer. It happens no matter if the screens are connected via the dock station or directly to DP port(s). Also it doesn't matter if suspend was triggered by closing the laptop lid or by the timer.

There are 2 ways I can avoid freezing after suspend:
1) Call "xrandr --auto" after I unplug external screens
2) Execute "sudo pm-suspend" manually

If I do one of the steps above suspend works perfectly and the laptop wakes up with no problems.

One thing to notice: while I was debugging this issue I put a script to the /etc/pm/sleep.d/ which simply logging the fact of its execution. When I'm using pm-suspend this script is being executed but if I simply close the lid then this script is not being executed. I believe when I'm closing the lid some other suspend mechanism is triggered not the pm-suspend.

I can confirm that this bug appeared in 16.04 LTS. I tried all kernels and all workarounds suggested in this post and none of them worked. Also I had same issue on previous Lenovo Carbon x1 rev (3).