From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=37021 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PAgv9-000138-5z for qemu-devel@nongnu.org; Tue, 26 Oct 2010 06:38:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PAgv7-0007wq-Qb for qemu-devel@nongnu.org; Tue, 26 Oct 2010 06:38:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30682) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PAgv7-0007wf-IM for qemu-devel@nongnu.org; Tue, 26 Oct 2010 06:38:21 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o9QAcKmO027397 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 26 Oct 2010 06:38:20 -0400 Date: Tue, 26 Oct 2010 12:38:18 +0200 From: Gleb Natapov Subject: Re: [Qemu-devel] [PATCH 0/2] Add get_dev_path callback to ISA bus. Message-ID: <20101026103818.GP2343@redhat.com> References: <1287928933-11423-1-git-send-email-gleb@redhat.com> <20101025170007.GC31633@redhat.com> <20101025180610.GA877@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: qemu-devel@nongnu.org On Tue, Oct 26, 2010 at 11:57:53AM +0200, Markus Armbruster wrote: > Gleb Natapov writes: > > > On Mon, Oct 25, 2010 at 07:53:41PM +0200, Markus Armbruster wrote: > >> Gleb Natapov writes: > >> > >> > On Mon, Oct 25, 2010 at 05:10:15PM +0200, Markus Armbruster wrote: > >> >> Gleb Natapov writes: > >> >> > >> >> > PCI bus already has one. For ISA bus this patch series uses device's > >> >> > ioports to uniquely describe it. For isa-ide, for example, get_dev_path > >> >> > method returns: > >> >> > 01f0-01f7,03f6 for first IDE controller > >> >> > 0170-0177,0376 for second one > >> >> > >> >> Any I/O port used by the device identifies it. I'd say a common > >> >> identifier is the "I/O base", the lowest I/O port used. > >> > So use only first port from the string. More information is better then > >> > less information. You can always drop information you do not need. > >> > >> I'd prefer canonical bus addresses to be terse. It's not the place to > >> give additional information. > > > > I'd prefer them to give full info but not more. I don't see why you > > point is more valid then mine. > > Full information about ISA resources is more than I/O ports, it also > includes IRQs and DMA channels. So you are arguing to add more info there? :) Theoretically there is nothing that prevents ISA devices from sharing IRQ line (existing ISA devices just not built to do that and nobody produces new once) and DMA is separate device on ISA bus AFAIK. > > An address is not the place to give full information. The purpose of an > address is to name a thing, not to give full information about that > thing. > Address should contain info that allows to find device easily. If whoever looking for a device knows only one port device is using he will not find the device if we'll use different port to name it. May be not the problem in practice. > > By the way, get_dev_path() really needs a written contract. Actually, > all the qdev and qbus callbacks do. What do you mean by that? It should be stable ABI, is this what you mean? -- Gleb.