From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Subject: Re: [PATCH] Documentation: bindings: net: DPAA corenet binding document Date: Wed, 3 Dec 2014 16:01:28 -0600 Message-ID: <1417644088.15957.235.camel@freescale.com> References: <1417169426-11823-1-git-send-email-madalin.bucur@freescale.com> <1417495189.15957.209.camel@freescale.com> <1417561420.15957.221.camel@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1417561420.15957.221.camel@freescale.com> Sender: netdev-owner@vger.kernel.org To: Bucur Madalin-Cristian-B32716 Cc: "devicetree@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "netdev@vger.kernel.org" , Medve Emilian-EMMEDVE1 , Liberman Igal-B31950 , "galak@codeaurora.org" , Shaohui Xie List-Id: devicetree@vger.kernel.org On Tue, 2014-12-02 at 17:03 -0600, Scott Wood wrote: > On Tue, 2014-12-02 at 06:12 -0600, Bucur Madalin-Cristian-B32716 wrote: > > > -----Original Message----- > > > From: Wood Scott-B07421 > > > Sent: Tuesday, December 02, 2014 6:40 AM > > > > > > No need for the part. As we previously discussed, the only > > > purpose of this node is backwards compatibility with the U-Boot MAC > > > address fixup -- if U-Boot doesn't look for the version, then > > > don't complicate things. > > > > > > Though, I can't find where U-Boot references this node. Are you sure > > > it's not using the ethernet%d aliases like everything else, in which > > > case why do we need this node at all? > > > > > > -Scott > > > > > > > The initial (Freescale SDK) binding document contained those compatibles, > > not sure what the initial intent was for the variants. > > > > The "fsl,dpaa" node is of interest to the DPAA Ethernet because it is > > the parent of the "fsl,dpa-ethernet" nodes. > > I'm not interested in what the SDK binding says, or what the SDK kernel > does. I'm interested in whether there's a U-Boot compatibility issue, > as was previously alleged. If there isn't, then there's no need for > fsl,dpaa *or* fsl,dpa-ethernet. OK, I found the U-Boot fixup in question. It's not for MAC addresses, but for marking disabled ports as disabled. It marks the dpa-ethernet node as disabled, based on it having an fsl,fman-mac property that points to the MAC node. U-Boot also disables the MAC node itself, so it doesn't matter if it doesn't find fsl,fman-mac -- except for the special case of fm1-dtsec1, which is always kept enabled because it's used for MDIO for all ports. Based on http://patchwork.ozlabs.org/patch/410770/ there's a separate node for mdio, so why can't we mark the MAC disabled? Assuming that there's no real problem in marking the fm1-dtsec1 MAC node disabled, we can consider this to be a bug in U-Boot which can be worked around by having the fm1-dtsec1 mac node have an fsl,fman-mac property that points to itself. This property would only go on the fm1-dtsec1 mac node and would only be in device trees for SoCs that are supported by U-Boots old enough to not have had the bug be fixed. -Scott