Comment 28 for bug 1390764

Exceuted the tracing steps suggested in https://wiki.ubuntu.com/DebuggingKernelSuspend using the latest mainline kernel

# uname -r
3.19.0-031900-generic

and everything worked as expected. The suspend state was entered seconds after running

# sync && echo 1 > /sys/power/pm_trace && pm-suspend

and the notebook resumed within seconds after pushing the power button. As usual the display returned fully dimmed and all controls to alter display brightness have no effect any more.

/proc/acpi/wakeup has not changed between suspend and resume. The RTC is skewed by nearly 21 years

# hwclock --show
Thu 19 Apr 1984 06:00:15 PM CEST -0.485252 seconds

indicating that some tracing information were put there. However, I can find only find one pair of

[ 1.981094] Magic number: 3:558:892
[ 1.981174] bdi default: hash matches

which was already included in dmesg before suspend, and doesn't quite match the pattern of what to watch out for. I am attaching dmesg output both gathered before and after suspend/resume.