From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758548Ab2CPDBL (ORCPT ); Thu, 15 Mar 2012 23:01:11 -0400 Received: from db3ehsobe003.messaging.microsoft.com ([213.199.154.141]:51854 "EHLO db3outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751226Ab2CPDBH convert rfc822-to-8bit (ORCPT ); Thu, 15 Mar 2012 23:01:07 -0400 X-SpamScore: -9 X-BigFish: VS-9(zzc89bh1432N98dKzz1202hzz8275chz2dh2a8h668h839hd25h) X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI Date: Fri, 16 Mar 2012 11:01:35 +0800 From: Dong Aisheng To: Lothar =?iso-8859-1?Q?Wa=DFmann?= CC: Dong Aisheng-B29396 , "s.hauer@pengutronix.de" , Guo Shawn-R65073 , "vinod.koul@linux.intel.com" , "devicetree-discuss@lists.ozlabs.org" , "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "rob.herring@calxeda.com" , Grant Likely , "rdunlap@xenotime.net" , "kernel@pengutronix.de" , "cjb@laptop.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH v1 1/5] ARM: imx28: add basic dt support Message-ID: <20120316030134.GA5161@shlinux2.ap.freescale.net> References: <1331628428-24017-1-git-send-email-b29396@freescale.com> <1331628428-24017-2-git-send-email-b29396@freescale.com> <20120313172351.97C5E3E053B@localhost> <20120314124512.GG1180@shlinux2.ap.freescale.net> <20120314141643.GP3852@pengutronix.de> <20120315030206.GB13022@shlinux2.ap.freescale.net> <20321.37353.63115.664975@ipc1.ka-ro> <20120315105927.GE13022@shlinux2.ap.freescale.net> <20321.53468.310199.875966@ipc1.ka-ro> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline In-Reply-To: <20321.53468.310199.875966@ipc1.ka-ro> User-Agent: Mutt/1.5.20 (2009-06-14) Content-Transfer-Encoding: 8BIT X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 15, 2012 at 07:22:04PM +0800, Lothar Waßmann wrote: > Hi, > > Dong Aisheng writes: > > On Thu, Mar 15, 2012 at 02:53:29PM +0800, Lothar Waßmann wrote: > > > Hi, > > > > > > Dong Aisheng writes: > > > > On Wed, Mar 14, 2012 at 10:16:43PM +0800, s.hauer@pengutronix.de wrote: > > > > > On Wed, Mar 14, 2012 at 08:45:23PM +0800, Dong Aisheng wrote: > > > > > > On Wed, Mar 14, 2012 at 01:23:51AM +0800, Grant Likely wrote: > > > [...] > > > > > > But it seems this needs pass mac address to fec driver via platforom data which is > > > > > > not friendly to dt. > > > > > > > > > > > > Another way may be changing fec driver to get the fixed part of mac address(first > > > > > > two bytes) from device tree and read the left dynamical part from otp which i'm not > > > > > > sure is better enough. > > > > > > > > > > > > BTW, filling with zeros seems not work since it's invalid mac address. > > > > > > > > > > Yes, that's the idea of using this value... > > > > > > > > > But comparing to use an invalid value, why not just do not define that > > > > local-mac-address property? > > > > > > > Because a MAC address is by definition a GLOBALLY UNIQUE IDENTIFIER > > > which is contrary to coding a "valid" default value for it somewhere! > > > The owner of a certain MAC address range (OUI) is responsible for > > > ensuring the uniqueness. Thus only they may assign a specific MAC > > > address to a specific device. > > > > > Yes, you're correct. > > So i propose to read the MAC address from MX28 OTP in fec driver instead of > > define it in device tree in my last mail. > > http://www.spinics.net/lists/arm-kernel/msg165040.html > > Do you have any comment on that way? > > > That patch sets the OUI to the Freescale owned MAC range. Thus only > Freescale products may be able to use the driver. > No. My proposal is only set the fixed part(first two octets) in board dts file, each board knows it's value, and read the left 4 octets from OCOTP dynamically. Obviously the freeescale board dts file is only for FSL platforms. Other platforms can define their fix part of MAC address in their dts file. > Anyway there is no definite spec how the MAC address(es) are stored > in the fuse map. Thus reading the MAC from there is more or less > platform specific. > It's just provide one more option since there are customers storing the MAC in the fuse map. > Currently I'm setting up the MAC address for our TX28 from the fuses > in the platform code passed via platform_data, but that will obviously > not work with DT. > Non-dt can also use my proposal, then you only need to pass the fixed part of MAC via platfrom data, the left will be read by fec driver. > The correct way would probably be to pass the MAC from the bootloader > via a DT blob. But that would require all bootloaders to be updated > first to support DTS. :( > But uboot will face the same problem that can not define a valid MAC in dts, did i undertand correctly? > An intermediate solution could be using OF_DEV_AUXDATA to pass a > platform_data struct that may contain a MAC address set up by the > platform code. > Yes, it's a way but i'm afraid will not get accepted by dt people. Regards Dong Aisheng