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)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4AE321A0D1F for ; Sat, 2 May 2015 01:23:01 +1000 (AEST) Message-ID: <1430493730.7979.58.camel@kernel.crashing.org> Subject: Re: [PATCH v4 19/21] drivers/of: Support adding sub-tree From: Benjamin Herrenschmidt To: Rob Herring Date: Sat, 02 May 2015 01:22:10 +1000 In-Reply-To: References: <1430460188-31343-1-git-send-email-gwshan@linux.vnet.ibm.com> <1430460188-31343-20-git-send-email-gwshan@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: "devicetree@vger.kernel.org" , "linux-pci@vger.kernel.org" , Gavin Shan , Grant Likely , Bjorn Helgaas , linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2015-05-01 at 07:54 -0500, Rob Herring wrote: > The difference seems to be whether you allocate space or just point to > the FDT for various strings/data. Is that right? > > > * of_fdt_add_subtree() is the introduced API to do the work. > > Have you looked at overlays and if so why do they not work for your purposes? > > Why do you need to do this with the flattened tree? The basic idea I asked Gavin to implement is that since the FW needs to provide a bunch of DT updates to Linux at runtime in the form of new nodes below an existing one, rather than doing it via some new/custom format, instead, have it send a bit of FDT blob to expand under an existing node. As for the details of Gavin implementation, I haven't looked at it in details yet so there might be issues there, however I don't know what you mean by "overlays", any pointer ? Cheers, Ben.