Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759619AbYFSSys (ORCPT ); Thu, 19 Jun 2008 14:54:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751671AbYFSSyh (ORCPT ); Thu, 19 Jun 2008 14:54:37 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:59200 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751555AbYFSSyg (ORCPT ); Thu, 19 Jun 2008 14:54:36 -0400 Date: Thu, 19 Jun 2008 12:54:19 -0600 From: Matthew Wilcox To: Stefan Richter Cc: Pekka J Enberg , Alan Stern , linux-kernel@vger.kernel.org, dsd@gentoo.org, mdharm-usb@one-eyed-alien.net, linux-usb@vger.kernel.org, vegardno@ifi.uio.no, James.Bottomley@HansenPartnership.com, linux-scsi@vger.kernel.org, Greg KH Subject: Re: [RFC/PATCH] usb-storage: wait for device scanning before mounting root Message-ID: <20080619185419.GN4392@parisc-linux.org> References: <48118DDD.8010507@s5r6.in-berlin.de> <20080425091122.GA14990@parisc-linux.org> <20080619182310.GA30833@parisc-linux.org> <485AA7EA.6080105@s5r6.in-berlin.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <485AA7EA.6080105@s5r6.in-berlin.de> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1706 Lines: 34 On Thu, Jun 19, 2008 at 08:39:38PM +0200, Stefan Richter wrote: > The problem is AFAIU not exactly how many Scsi_Host instances (initiator > port representations, or something remotely related to that) are > instantiated, but rather _when_ they are instantiated. On multi > protocol buses or networks like USB and FireWire, it makes sense to > create the SCSI initiator port representation when we discovered that > there are actually SCSI targets on the bus or network. I'm not convinced of that. Why shouldn't we create one scsi host for all USB scsi devices? I know that today there's a certain amount of per-device state stored in the scsi_host, but that should be fixable. > scsi_scan's API is geared towards drivers which create one or more > initiator port representations right up front before going on target > discovery, right? Today, yes. The mail that I just pinged described a way to enhance the API -- letting you tell scsi "I've started scanning, save me a place in the queue" and "I've finished scanning, hook me up". The advantage to this is that you can spend a lot more time waiting for devices without increasing boot time significantly, since you wait while the rest of the system initialises. -- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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/