UME deep sleep time is not enough while idle

[Yu Ping]

Description:
using powertop to check the C state, and found that the deep state time is around 30ms, which is not long enough. Note: we have removed USB NIC, USB mouse etc.
the biggest 3 event is:
rescheduling interrupt <kenrel IPI> ( this event is not in moblin, and seems like the root cause?)
usb_hcd_poll_rh_status <kernel module>
extra timer interrupt<interrupt>

Reproduce Steps:
(1)remove USB NIC, USB mouse etc.
(2)using powertop to check the C state

Expected Result:
the deep C state should be longer

[Alvaro Kuolas (kuolas)]

I'm experiencing the same thing on Ubuntu 8.04 "Hardy". No PCMCIA and no Yenta_socket.