This all started happening after upgrading to 13.10, now I am running 14.04 and still have the same issue.

When I close the lid or I do sudo pm-suspend the laptop goes into suspend for 2-5 seconds and awakes by itself.

Same happens if I try to do hibernate.

I have a gut feeling that something is awaking/taking the cpu out of suspend mode but I cannot figure out what.

Any help troubleshooting this annoying issue?

Edit:

Thanks to @Fabian , I was able to figure out that it looks like the ethernet card is misbehaving and even after I set the card to not wake up on lan (either doing acpitool -W 3 or echo disabled > /sys/bus/pci/devices/0000:00:19.0/power/wakeup or echo IGBE > /proc/acpi/wakeup, the laptop keeps waking up and showing this when I do acpitool -w

Device  S-state   Status   Sysfs node

---------------------------------------

1. LID    S3    *enabled 

2. SLPB   S3    *disabled

3. IGBE   S4    *enabled   pci:0000:00:19.0

4. EXP1   S4    *disabled  pci:0000:00:1c.0

5. EXP2   S4    *disabled  pci:0000:00:1c.1

6. EXP3   S4    *disabled

7. EXP4   S4    *disabled

8. EXP5   S4    *disabled  pci:0000:00:1c.4

9. EHC1   S3    *disabled  pci:0000:00:1d.0

10. EHC2      S3    *disabled  pci:0000:00:1a.0

11. HDEF      S4    *disabled  pci:0000:00:1b.0

Any idea how to proceed from there?

The network driver that IGBE uses is e1000e