Comment 26 for bug 287453

If you are experiencing this issue (kernel reporting a slow resume - more than 5 seconds) there are several potential causes, at least two of which are expected (1 & 2) and the warning is something of a false positive.

1. Several devices pushing the resume time slightly beyond the arbitrary 5-second boundary
2. Hard disks taking some time to become ready - see bug #318978
3. Device(s) requesting a firmware file to be loaded whilst user-space is still frozen (the delay will be around 60 seconds in this case) - see bug #331415
4. Some device or driver suffering specific problems with resume.

To determine if the warnings you see are 'real' problems please run this small shell script and copy the results to a comment here.

for log in /var/log/kern.log*; do CMD="cat "; echo $log; [ ! ${log##*.gz} ] && CMD="zcat "; $CMD $log | grep -n 'PM: suspend devices took'; done

Example output:

/var/log/kern.log
/var/log/kern.log.0
3678:Feb 19 06:06:56 hephaestion kernel: [60285.296215] PM: suspend devices took 3.752 seconds
3948:Feb 19 10:19:23 hephaestion kernel: [75478.752211] PM: suspend devices took 3.752 seconds
/var/log/kern.log.1.gz
/var/log/kern.log.2.gz
/var/log/kern.log.3.gz

Basically, if you see a resume time close to but just over 5 seconds, it is likely there is no real problem - it's just the kernel taking a lets-be-cautious approach, e.g.:

PM: resume devices took 5.148 seconds

If there are no other kernel Oops messages besides the suspend_test_finish() then you can safely ignore the warning.