From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e3.ny.us.ibm.com (e3.ny.us.ibm.com [32.97.182.143]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e3.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTP id C98E6DDE35 for ; Wed, 5 Sep 2007 13:05:59 +1000 (EST) Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e3.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id l8535ubs011369 for ; Tue, 4 Sep 2007 23:05:56 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id l8535uYh408546 for ; Tue, 4 Sep 2007 23:05:56 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l8535uKu014496 for ; Tue, 4 Sep 2007 23:05:56 -0400 Subject: Re: [patch 3/6] Walnut DTS From: Josh Boyer To: David Gibson In-Reply-To: <20070905023612.GD17189@localhost.localdomain> References: <20070831200449.598781000@linux.vnet.ibm.com> <20070831200643.202414000@linux.vnet.ibm.com> <20070903010859.GD31499@localhost.localdomain> <1188741584.3772.7.camel@localhost.localdomain> <20070904074203.748030c7@weaponx.rchland.ibm.com> <20070905023612.GD17189@localhost.localdomain> Content-Type: text/plain Date: Tue, 04 Sep 2007 19:39:26 -0500 Message-Id: <1188952766.3223.3.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2007-09-05 at 12:36 +1000, David Gibson wrote: > On Tue, Sep 04, 2007 at 07:42:03AM -0500, Josh Boyer wrote: > > On Sun, 02 Sep 2007 08:59:44 -0500 > > Josh Boyer wrote: > [snip] > > > > > + POB0: opb { > > > > > + compatible = "ibm,opb"; > > > > > > > > Need an opb-405gp here, too. > > > > > > Yep. > > > > Fixed. > > > > > > > + #address-cells = <1>; > > > > > + #size-cells = <1>; > > > > > + ranges = <0 ef600000 a00000>; > > > > > > > > Hrm... something we ought to clarify is the interpretation of the > > > > POB0_BEAR register with respect to the bridge's ranges property. For > > > > 440 I think the BEAR will need to be interpreted as an OPB address, > > > > rather than a PLB address, but I'm not sure if that will work here > > > > with the limited ranges property you have. > > > > > > Ok, I'll look at this. > > > > The BEAR will still be interpreted as a PLB address here as far as I > > can see. The ranges spans the entire OPB space. Am I missing > > something? > > Ah, sorry, my mistake. I thought the BEAR register would encode an > OPB address rather than a PLB address (and thus, be only 32-bits wide > on 440). In fact it appears it does encode a PLB address (and is > split into BEARH and BEARL registers on 440). Right. > Hrm.. I'm still slightly uneasy though. In my Ebony device tree, the > POB's ranges exists to embed the 32-bit OPB space into the 64-bit PLB > space by tacking on a 0x1 in bits 32:35. In your 405gp ranges, you're > describing just the address range used by OPB peripherals > (0xef600000-0xf0000000) as residing at address 0 in OPB-space. > > Since the ranges will still generate the right physical addresses, I > guess it doesn't matter. But I'm not sure it meets the principle of > least surprise - since I think the documentation generally talks as > though addresses on the 405 OPB bus are identical to addreses on the > PLB. I don't care either way. If I remember correctly, this way of doing it came out of a discussion with Segher. josh