When I try to put my Ubuntu 10.10 box to sleep or into hibernation, it appears to wake up right away (couple of seconds at most). I am trying to figure out what's going on, and would appreciate any suggestions.
syslog says:
Dec 12 13:15:25 mig kernel: [13049.728355] pm_op(): usb_dev_suspend+0x0/0x20 returns -2 Dec 12 13:15:25 mig kernel: [13049.728357] PM: Device usb3 failed to suspend async: error -2 Dec 12 13:15:25 mig kernel: [13049.728451] PM: Some devices failed to suspend
Now, how do I find out which device is usb3 and why it's failing to suspend?
The only external USB device in the system is a dongle for wireless keyboard and mouse. If I disconnect it, ssh into the box and run pm-suspend, it still fails with exactly the same error message.
lsusb gives:
Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
so the setup isn't exactly extravagant. The mobo is Asus P7P55D-E based on the P55 Express chipset.
edit It turns out usb3 wasn't the name of a device but was a reference to the USB 3.0 protocol. If I disable the latter in the BIOS, the box can sleep!
This is cross-posted from superuser.com, since there are no answers there and the question is Ubuntu-specific.

syslogwhich (inexplicably!) I was overlooking before. I'll update the question. – NPE Dec 12 '10 at 13:17