From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: adding OF_DYNAMIC proc interface Date: Fri, 28 Sep 2012 15:54:13 -0600 Message-ID: <50661C85.4000209@wwwdotorg.org> References: <1348850798-24352-1-git-send-email-atull@altera.com> <1348867740.7621.4.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1348867740.7621.4.camel@pasglop> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Benjamin Herrenschmidt Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, atull@atull-linux1, Rob Herring List-Id: devicetree@vger.kernel.org On 09/28/2012 03:29 PM, Benjamin Herrenschmidt wrote: > On Fri, 2012-09-28 at 11:46 -0500, Alan Tull wrote: >> Hello, >> >> The following patch adds a /proc/ofdt interface to add or remove device tree >> nodes dynamically. >> >> Based on earlier feedback, I've changed my driver to use /proc instead of >> creating a new ioctl (the old thread is at >> http://www.mail-archive.com/devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org/msg17333.html) >> >> >> I was hoping to get some early feedback from others who might be interested >> who were discussing this on an earlier thread about OF_DYNAMIC usage. >> >> This code doesn't do any notification for drivers yet. It can add multiple >> nodes and they will show up properly under /proc/device-tree. It has an >> issue that shows up when removing nodes (it appears that the memory used by >> proc gets corrupted after the add). > > (Adding Arnd here) > > Have you guys considered whether a better approach would be a file > system ? IE, create a node by creating a directory, add files for > properties etc... ? > > It might need some trick to make the node "active" (in order to not > internally in the kernel start exposing unfinished nodes), maybe a > special file, maybe a permission trick ... mkdir automatically creates status="disabled" or similar internally to the kernel?