Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756416AbcDNQKu (ORCPT ); Thu, 14 Apr 2016 12:10:50 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:34366 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756361AbcDNQKr (ORCPT ); Thu, 14 Apr 2016 12:10:47 -0400 Message-ID: <570FC104.80808@gmail.com> Date: Thu, 14 Apr 2016 09:10:44 -0700 From: Frank Rowand Reply-To: frowand.list@gmail.com User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Pantelis Antoniou CC: Mark Rutland , Russell King - ARM Linux , Rob Herring , Masahiro Yamada , devicetree@vger.kernel.org, Arnd Bergmann , Linux Kernel Mailing List , linux-arm-kernel Subject: Re: [Question] refcount of DT node References: <20160414084849.GT19428@n2100.arm.linux.org.uk> <20160414095957.GB10273@leverpostej> <06E9E2D3-4627-4970-ABBB-34B5ED620709@konsulko.com> In-Reply-To: <06E9E2D3-4627-4970-ABBB-34B5ED620709@konsulko.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1775 Lines: 55 On 4/14/2016 3:02 AM, Pantelis Antoniou wrote: > Hi Mark, > >> On Apr 14, 2016, at 12:59 , Mark Rutland wrote: >> >> On Thu, Apr 14, 2016 at 09:48:49AM +0100, Russell King - ARM Linux wrote: >>> On Thu, Apr 14, 2016 at 04:47:57PM +0900, Masahiro Yamada wrote: >>>> Hi experts. >>>> >>>> My understanding of refcount of DT node is poor. >>> >>> The message from DT people is... don't worry about DT node refcounting. >>> Do whatever you want with it, they don't care whether you have correct >>> refcounting or not. >>> >>> The background behind that is that I've tried to fix the refcounting, >>> and even had the coccinelle people generate some stuff to work on this >>> issue, but DT people's attitude towards it is "don't bother". >>> >>> So yes, people may get it wrong, but it seems it's something that DT >>> people want ignored. >> >> I'm not sure that's quite fair; the last discussion I recall about this >> ended up concluding that we need a better API, rather than papering over >> problems. >> >> That said, there isn't much obvious progress on that front. >> >> Frank, Pantelis, Rob, were there any conclusions on this from ELC, or is >> this something that needs someone to propose something? >> > > Frank mentioned that he wants a new API. I have some ideas about it too. > > My take is that drivers should never do reference counting, we have to figure > out a way for DT access using copy semantics or locks. > > References would still be required for core DT code, but that’s a sane subset. Yes. Nothing concrete about implementation was decided at ELC, but this issue is on my todo list. -Frank > >> Mark. >> >> [1] http://permalink.gmane.org/gmane.linux.drivers.devicetree/153777 > > Regards > > — Pantelis > > . >