From owner-freebsd-usb@FreeBSD.ORG Tue Feb 17 15:55:20 2009 Return-Path: Delivered-To: freebsd-usb@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CE71510656E4 for ; Tue, 17 Feb 2009 15:55:20 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from harmony.bsdimp.com (bsdimp.com [199.45.160.85]) by mx1.freebsd.org (Postfix) with ESMTP id 7DC5F8FC21 for ; Tue, 17 Feb 2009 15:55:20 +0000 (UTC) (envelope-from imp@bsdimp.com) Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.2/8.14.1) with ESMTP id n1HFsHtX030501; Tue, 17 Feb 2009 08:54:18 -0700 (MST) (envelope-from imp@bsdimp.com) Date: Tue, 17 Feb 2009 08:54:24 -0700 (MST) Message-Id: <20090217.085424.775975548.imp@bsdimp.com> To: hselasky@c2i.net From: "M. Warner Losh" In-Reply-To: <200902170856.11631.hselasky@c2i.net> References: <20090216.190312.1756925299.imp@bsdimp.com> <7F91349C-7E58-47C8-BB69-3B2F391B4E73@mac.com> <200902170856.11631.hselasky@c2i.net> X-Mailer: Mew version 5.2 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: freebsd-usb@FreeBSD.org Subject: Re: USB2+umass: root mount fails X-BeenThere: freebsd-usb@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: FreeBSD support for USB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Feb 2009 15:55:21 -0000 In message: <200902170856.11631.hselasky@c2i.net> Hans Petter Selasky writes: : On Tuesday 17 February 2009, Marcel Moolenaar wrote: : > On Feb 16, 2009, at 6:03 PM, M. Warner Losh wrote: : > > : root_mount_hold() and root_mount_rel() are specifically : > > : designed to inform the mountroot code that it needs to : > > : wait (or that it should go ahead and mount root). : > > : > > But it looks like the old usb code didn't call it either... I think : > > old code enumerated right away during boot, while the new code defers : > > the enumeration until events can be processed... : > : > Yes, you're right. USB1 used the following: : > : > SYSINIT(usb_cold_explore, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE, : > usb_cold_explore, NULL); : > : > SI_SUB_CONFIGURE didn't complete before all USB busses : > were enumerated. : : I would really prefer that first time USB enumeration is not synchronous. This : has to do with startup timing. It simply wastes a lot of time to wait for all : the busses to be probed in serial. Sure it works nice with a USB keyboard and : a USB mouse, but when you have a couple of USB HUBs and +8 devices connected, : it simply speeds up the boot time so that you reach the root prompt by the : time you would else have done the mount root mfs. : : If the mountroot code cannot find the disk, it should sleep and loop. I think this is a weak argument. I'm strongly in favor of the usb1 behavior here. Warner