Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261489AbTEMPYj (ORCPT ); Tue, 13 May 2003 11:24:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261506AbTEMPYj (ORCPT ); Tue, 13 May 2003 11:24:39 -0400 Received: from h-68-165-86-241.DLLATX37.covad.net ([68.165.86.241]:5927 "EHLO sol.microgate.com") by vger.kernel.org with ESMTP id S261489AbTEMPYd (ORCPT ); Tue, 13 May 2003 11:24:33 -0400 Subject: Re: 2.5.69 Interrupt Latency From: Paul Fulghum To: Alan Stern Cc: Greg KH , Andrew Morton , "linux-kernel@vger.kernel.org" , Arnd Bergmann , johannes@erdfelt.com In-Reply-To: References: Content-Type: text/plain Organization: Message-Id: <1052840106.2255.24.camel@diemos> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-4) Date: 13 May 2003 10:35:07 -0500 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1319 Lines: 32 On Tue, 2003-05-13 at 10:26, Alan Stern wrote: > Putting in a sanity check for the global suspend state will be very easy. > But I would like to point out that this "global suspend" does not refer to > the entire system, only the USB bus. That is a problem then, because the delay can still occur during normal system operation. > I'm not sure under what > circumstances the bus is placed in global suspend; I think it's just when > there are no devices attached (or the last remaining device is detached). > > However, there have been cases on my own system where turning off the only > USB peripheral caused the driver to bounce between suspend_hc() and > wakeup_hc() several times without any apparent explanation -- possibly as > a result of transient electrical signals on the bus (?). So perhaps > moving that delay out of the ISR isn't such a bad idea. Agreed. If this can happen on functional USB controllers when no devices are attached, then it is a serious problem. -- Paul Fulghum, paulkf@microgate.com Microgate Corporation, http://www.microgate.com - 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/