Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757073AbYKUS4o (ORCPT ); Fri, 21 Nov 2008 13:56:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752159AbYKUS4g (ORCPT ); Fri, 21 Nov 2008 13:56:36 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:52285 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751942AbYKUS4g (ORCPT ); Fri, 21 Nov 2008 13:56:36 -0500 Date: Fri, 21 Nov 2008 13:56:32 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Yi Yang cc: David Brownell , "linux-kernel@vger.kernel.org" , "gregkh@suse.de" , "akpm@linux-foundation.org" Subject: Re: [PATCH] USB: improve ehci_watchdog's side effect in CPU power management In-Reply-To: <1227279337.3447.22.camel@yangyi-dev> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 667 Lines: 18 On Fri, 21 Nov 2008, Yi Yang wrote: > But on Asus EeePC, i saw another periodical timer usb_hcd_poll_rh_status > which fires every 256 milisecond, is this also doing with some > hardware's quirk? That timer is associated mostly with UHCI controllers. It is not because of a hardware quirk. If the controller is suspended (for example, because no devices are attached to it) then the timer should stop. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/