From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id E119A67B27 for ; Tue, 20 Jun 2006 11:18:21 +1000 (EST) Subject: Re: [RFC] Interrupt mapping documentation From: Benjamin Herrenschmidt To: Becky Bruce In-Reply-To: <40AABEB6-3467-4AFB-BC7B-08176EDD61E2@freescale.com> References: <1150598731.23600.146.camel@localhost.localdomain> <3E324A7E-388E-4917-B380-B0831A5F9D19@kernel.crashing.org> <1150759075.23600.297.camel@localhost.localdomain> <40AABEB6-3467-4AFB-BC7B-08176EDD61E2@freescale.com> Content-Type: text/plain Date: Tue, 20 Jun 2006 11:18:06 +1000 Message-Id: <1150766286.23600.316.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > If there's precedence for it, it's fine with me. I was just curious > about why it changed. Personally, I'd rather see it as "pic", > because that's more specific, and it's the actual device name, but > it's not keeping me up at night..... I'll revert the example to "pic". I thing Segher is right, let's leave some freedom there. > That also works for me. I'd rather have to specify more stuff in the > tree and have it be crystal clear how it's interpreted and used. So, > is this true for just #address-cells, or does it affect #size-cells > as well? Yes. The OF spec says that #size-cells defaults to 1 when absent but I'd rather make it mandatory. It's not used for interrupt tree resolving though thus it's not necessary in interrupt-controller nodes. > Sounds good. The dtc should probably throw an error (or at least a > warning) on this, so the trees get fixed. I think I'd prefer to see > an error - that will keep this problem from propagating any further. Yup. > > In the case of interrupt controllers/nexus, #address-cells is not for > > addressable sub-nodes though but for defining the format of unit > > interrupt specifiers for interrupt-childs which aren't necessary sub > > nodes... confusing heh ? > > Um, yeah :) I think with a little clarification it will be fine, > though. Yeah, it's a bit complicated and I'm not that good at writing very clear english :) I'll try to do a second pass on that part of the spec. In fact, the only case where #address-cells is required in an interrupt controller node (and that node is a leaf node, not also a bus), is when an interrupt nexus points to it (that is an interrupt-map). I should make that clear in the spec. If you don't use interrupt maps, you should not need that #address-cells in the interrupt-controller. Ben.