For some reason my system now refuses to sleep/shut down when using the Intel graphics card (using the NVIDIA card is fine). The laptop is based on Intel Skylake. The graphics card is Intel HD Graphics 530.
I'm on 16.04 LTS and kernel 4.4.19-040419-generic.
I'd like to provide more information if possible but unfortunately the only thing I see is a black screen and an empty command prompt at the first line. The laptop gets stuck at that stage and nothing is further shown. I have hold the power button every time to shut it down. Maybe there are some other ways for me to collect debug information?