From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762187AbXGUDsb (ORCPT ); Fri, 20 Jul 2007 23:48:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755404AbXGUDsX (ORCPT ); Fri, 20 Jul 2007 23:48:23 -0400 Received: from static-71-162-243-5.phlapa.fios.verizon.net ([71.162.243.5]:41455 "EHLO grelber.thyrsus.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754015AbXGUDsW (ORCPT ); Fri, 20 Jul 2007 23:48:22 -0400 From: Rob Landley Organization: Boundaries Unlimited To: Greg KH Subject: Re: Documentation for sysfs, hotplug, and firmware loading. Date: Fri, 20 Jul 2007 23:48:14 -0400 User-Agent: KMail/1.9.6 Cc: Cornelia Huck , Kay Sievers , linux-kernel@vger.kernel.org, Michael-Luke Jones , Krzysztof Halasa , Rod Whitby , Russell King , david@lang.hm References: <200707171703.31340.rob@landley.net> <20070720095401.68e9ce03@gondolin.boeblingen.de.ibm.com> <20070720080936.GA22047@kroah.com> In-Reply-To: <20070720080936.GA22047@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707202348.14759.rob@landley.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 20 July 2007 4:09:36 am Greg KH wrote: > On Fri, Jul 20, 2007 at 09:54:01AM +0200, Cornelia Huck wrote: > > On Fri, 20 Jul 2007 00:00:01 -0700, > > > > Greg KH wrote: > > > > I don't insist on it, mknod insists on it. You cannot mknod a dev > > > > node without specifying block or char. > > > > > > > > You're saying that sysfs should provide major and minor numbers > > > > without anywhere specifying "char" or "block", meaning the major and > > > > minor numbers cannot be _used_. I am insisting on getting the third > > > > piece of information without which "major" and "minor" are useless. > > > > > > > > I asked very specifically about this at OLS, several times. What > > > > you're telling me now seems to contradict what you told me then. > > > > > > Here's the rule: > > > If the SUBSYSTEM is "block", it's a block device. Otherwise > > > it's a char device. > > > > That's actually quite confusing to the casual reader, since: > > > But also realize that the majority of events you will get have nothing > > > to do with device nodes. I think you are forgetting this fact. > > > > So the rule should be: > > If the SUBSYSTEM is "block" (implying major/minor are provided), > > it's a block device. > > If the SUBSYSTEM is not "block", and major/minor are provided, > > it's a char device. > > If major/minor are not provided, the event/device is not > > relevant to device node creation. > > Yes, that is much more descriptive, thanks. agreed, thanks. I'll try to post an updated version of my hotplug documentation later tonight. (Just a _touch_ jetlagged at the moment, though. It may only be 9:47 california time, but it's 11:47 on the east cost. I think.) > greg k-h Rob -- "One of my most productive days was throwing away 1000 lines of code." - Ken Thompson.