tree bc1a60dac25eef26e22d346ebf08496b7702ac94
parent e58dcebcd83b5902411e747ee7807219dee6bcf2
author Yi Yang <yi.y.yang@intel.com> 1222334744 +0800
committer Greg Kroah-Hartman <gregkh@suse.de> 1224279662 -0700

USB: improve ehci_watchdog's side effect in CPU power management

ehci_watchdog will wake up CPU very frequently so that CPU
stays at C3 very short, average residence time is about 50
ms on Aspire One, but we expect it should be about 1 second
or more, so this kind of periodic timer is very bad for power
saving.

We can't remove this timer because of some bad USB controller
chipset, but at least we should reduce its side effect to as
possible as low.

This patch can make CPU stay at C3 longer, average residence time
is about twice as long as original. 

Please consider to apply it, thanks

Signed-off-by: Yi Yang <yi.y.yang@intel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>