From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932775Ab0JYUHA (ORCPT ); Mon, 25 Oct 2010 16:07:00 -0400 Received: from edu-smtp-02.edutel.nl ([88.159.1.176]:50341 "EHLO edu-smtp-02.edutel.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757583Ab0JYUG7 (ORCPT ); Mon, 25 Oct 2010 16:06:59 -0400 Message-ID: <4CC5E354.80009@neli.hopto.org> Date: Mon, 25 Oct 2010 22:06:44 +0200 From: Micha Nelissen User-Agent: Mozilla-Thunderbird 2.0.0.22 (X11/20091109) MIME-Version: 1.0 To: "Bounine, Alexandre" CC: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Matt Porter , Li Yang , Kumar Gala , Thomas Moll Subject: Re: [PATCH -mm 0/2] RapidIO: Changes to handling of RIO switches References: <1287688250-14226-1-git-send-email-alexandre.bounine@idt.com> <4CC0AD74.8070800@neli.hopto.org> <0CE8B6BE3C4AD74AB97D9D29BD24E55201445906@CORPEXCH1.na.ads.idt.com> <4CC1D7DE.7060405@neli.hopto.org> <0CE8B6BE3C4AD74AB97D9D29BD24E55201445A6B@CORPEXCH1.na.ads.idt.com> <4CC20923.8050400@neli.hopto.org> <0CE8B6BE3C4AD74AB97D9D29BD24E55201445BA4@CORPEXCH1.na.ads.idt.com> <4CC5ACAB.7070309@neli.hopto.org> <0CE8B6BE3C4AD74AB97D9D29BD24E5520147D5C2@CORPEXCH1.na.ads.idt.com> In-Reply-To: <0CE8B6BE3C4AD74AB97D9D29BD24E5520147D5C2@CORPEXCH1.na.ads.idt.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Bounine, Alexandre wrote: > Micha Nelissen wrote: >> that switch. The tag uses one extra bit to identify the device as a >> switch instead of an endpoint. This provides the information to >> unambiguously identify a switch from an endpoint. > > OK taking away #2. But do not see how it justifies storing two values of > destid. I look at it this way: it prevents the need for another layer of indirection: translating component tag to a destid. > And you have just confirmed using CT for unique identification. That's correct, but I never said (intended to say) I didn't. > We > simply have differences in interpretation of CT: you are using component > tag to pass unique identification and I am using CT as a unique > identification. I prefer not to assume any relationship between routing > information and the component tag. Why no relation? My experience is that during debugging it's useful to have the destid directly at hand, it's just very practical. (Otherwise any drawing of a random network would need two "identification" numbers per drawn node: the component tag (true identification), and destid since that's what everyone uses to identify a device, what needs to programmed into the LUTs of a switch, identification in sysfs, etc.). Micha