Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751819Ab3IPWqn (ORCPT ); Mon, 16 Sep 2013 18:46:43 -0400 Received: from co9ehsobe004.messaging.microsoft.com ([207.46.163.27]:52983 "EHLO co9outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751775Ab3IPWqk (ORCPT ); Mon, 16 Sep 2013 18:46:40 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: -5 X-BigFish: VS-5(zzbb2dI98dI9371I936eI1432Izz1f42h208ch1ee6h1de0h1fdah2073h1202h1e76h1d1ah1d2ah1fc6hzzz2dh2a8h839h93fhd24hf0ah1288h12a5h12a9h12bdh137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1b2fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e23h1fe8h1ff5h1155h) Message-ID: <1379371590.2536.187.camel@snotra.buserror.net> Subject: Re: [PATCH v9 2/3] DMA: Freescale: Add new 8-channel DMA engine device tree nodes From: Scott Wood To: Mark Rutland CC: Hongbo Zhang , "devicetree@vger.kernel.org" , "ian.campbell@citrix.com" , Pawel Moll , "swarren@wwwdotorg.org" , "vinod.koul@intel.com" , "linux-kernel@vger.kernel.org" , "rob.herring@calxeda.com" , "djbw@fb.com" , "linuxppc-dev@lists.ozlabs.org" Date: Mon, 16 Sep 2013 17:46:30 -0500 In-Reply-To: <20130912171541.GH22013@e106331-lin.cambridge.arm.com> References: <1377861980-7027-1-git-send-email-hongbo.zhang@freescale.com> <1377861980-7027-3-git-send-email-hongbo.zhang@freescale.com> <20130902155636.GA18206@e106331-lin.cambridge.arm.com> <5225A57E.4030003@freescale.com> <20130912171541.GH22013@e106331-lin.cambridge.arm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1414 Lines: 31 On Thu, 2013-09-12 at 18:15 +0100, Mark Rutland wrote: > On Tue, Sep 03, 2013 at 10:01:50AM +0100, Hongbo Zhang wrote: > > On 09/02/2013 11:58 PM, Mark Rutland wrote: > > > May some channels be unusable for some reason, or will all eight > > > channels be wired on any given Elo3 DMA? > > Sorry, not get your point clearly, maybe you are clear now because of my > > previous explanations. > > I assume that on any El03 DMA, there won't be a case where you can't > describe the channel at 0x80, for instance. It will always be present > (but it might not be wired up to anything any therefore be useful)? > > This was related to my concerns about the status register description -- > if the channels at 0x0,0x80,0x100,0x180 weren't wired, what would get > described in the dt? I guess that would never actually happen because > all 8 channels must always be present in the Elo3 IP block. If a channel is not usable for whatever reason (other than that "used for a different fixed purpose and thus described with a different compatible" thing that was mentioned earlier in these threads), wouldn't it just have status = "disabled" or similar, or be absent? -Scott -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/