Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756864AbYH1AEk (ORCPT ); Wed, 27 Aug 2008 20:04:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754833AbYH1AE3 (ORCPT ); Wed, 27 Aug 2008 20:04:29 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:44846 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754312AbYH1AE2 (ORCPT ); Wed, 27 Aug 2008 20:04:28 -0400 Date: Wed, 27 Aug 2008 16:48:49 -0700 From: Greg KH To: Alan Stern Cc: Oliver Neukum , USB list , Stefan Kopp , Marcel Janssen , Felipe Balbi , Kernel development list Subject: Re: [PATCH] USB: add USB test and measurement class driver - round 2 Message-ID: <20080827234849.GD31264@kroah.com> References: <200808272105.50169.oliver@neukum.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1763 Lines: 42 On Wed, Aug 27, 2008 at 03:16:18PM -0400, Alan Stern wrote: > On Wed, 27 Aug 2008, Oliver Neukum wrote: > > > Am Mittwoch 27 August 2008 20:58:08 schrieb Alan Stern: > > > > And this rule depends on sharing the USB major or not. This needs > > > > a big fat mention in Documentation. > > > > > > You mean that the open/disconnect locking rule applies only to drivers > > > that call usb_register_dev, i.e, drivers using the USB major. ?Right? > > > > Yes. In fact drivers not using the USB major but their own char devices > > will need such a lock. This is tricky. > > IMO all char-device registration/deregistration routines should use a > similar rwsem. Then device drivers wouldn't need to worry about it. > > > > I agree that it deserves to be mentioned in the documentation > > > somewhere. ?Where would be a good place? ?None of the existing files in > > > Documentation/usb seem appropriate. > > > > The USB major merits a file of its own. > > I don't feel competent to start writing such a file. Greg, what do you > think? Maybe all that's needed to get going is to "borrow" some of the > material in LDD3. :-) Well, as the USB chapter in LDD3 "borrowed" heavily from the comments in the usb code itself, that would only be fair :) That chapter needs to be reworked. The authors and Oreilly and I are currently talking about how to do this all in a framework that makes sense (the current one of a book every few years that quickly gets out of date doesn't make sense.) thanks, greg k-h -- 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/