From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756989Ab2AXRZ0 (ORCPT ); Tue, 24 Jan 2012 12:25:26 -0500 Received: from cantor2.suse.de ([195.135.220.15]:41535 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755932Ab2AXRZZ (ORCPT ); Tue, 24 Jan 2012 12:25:25 -0500 Date: Tue, 24 Jan 2012 09:22:31 -0800 From: Greg KH To: Sebastian Andrzej Siewior Cc: Alan Stern , Simon Glass , LKML , linux-usb@vger.kernel.org, Sarah Sharp Subject: Re: [PATCH] usb: Use a workqueue in usb_add_hcd() to reduce boot time Message-ID: <20120124172231.GA27273@suse.de> References: <20120124165711.GC3836@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120124165711.GC3836@linutronix.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 24, 2012 at 05:57:11PM +0100, Sebastian Andrzej Siewior wrote: > * Alan Stern | 2012-01-21 11:11:09 [-0500]: > > >Doing time-consuming things later won't make any difference. That is, > >suppose the boot sequence performs activities A and B, where A takes a > >long time. Doing A later, so that the boot sequence performs B and > >then A, won't change the total time required. > > That is true. However if you show the gui _now_ and look for USB later > then it feels faster and this is usually enough. Which has been done before, with great success (i.e. we did it for Moblin boot times), so it shouldn't be that big of an issue. Which points out the question, exactly what is the issue here? We have "multithreaded" pci driver startup for a long time now, did that stop working here? If you use bootchart, does it show that the USB host driver is stoping the machine from proceeding to the next stage in the boot process? >>From my experience, I never saw the USB host controller get in the way at all, it was always somethine else happening that caused problems (i.e. video.) Simon, do you have boot charts anywhere showing this? thanks, greg k-h