From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83AFAC561F8 for ; Wed, 21 Oct 2020 09:38:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2FA1221D7B for ; Wed, 21 Oct 2020 09:38:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438188AbgJUJiG (ORCPT ); Wed, 21 Oct 2020 05:38:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437415AbgJUJiG (ORCPT ); Wed, 21 Oct 2020 05:38:06 -0400 Received: from hillosipuli.retiisi.eu (hillosipuli.retiisi.eu [IPv6:2a01:4f9:c010:4572::81:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29940C0613CE; Wed, 21 Oct 2020 02:38:06 -0700 (PDT) Received: from valkosipuli.localdomain (valkosipuli.retiisi.org.uk [IPv6:2a01:4f9:c010:4572::80:2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by hillosipuli.retiisi.eu (Postfix) with ESMTPS id 48E78634C8E; Wed, 21 Oct 2020 12:37:58 +0300 (EEST) Received: from sailus by valkosipuli.localdomain with local (Exim 4.92) (envelope-from ) id 1kVAZD-0000e6-Du; Wed, 21 Oct 2020 12:37:59 +0300 Date: Wed, 21 Oct 2020 12:37:59 +0300 From: Sakari Ailus To: Andy Shevchenko Cc: Dan Scally , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux.walleij@linaro.org, prabhakar.mahadev-lad.rj@bp.renesas.com, heikki.krogerus@linux.intel.com, dmitry.torokhov@gmail.com, laurent.pinchart+renesas@ideasonboard.com, kieran.bingham+renesas@ideasonboard.com, jacopo+renesas@jmondi.org, robh@kernel.org, davem@davemloft.net, linux@rasmusvillemoes.dk, sergey.senozhatsky@gmail.com, rostedt@goodmis.org, pmladek@suse.com, mchehab@kernel.org, tian.shu.qiu@intel.com, bingbu.cao@intel.com, sakari.ailus@linux.intel.com, yong.zhi@intel.com, rafael@kernel.org, gregkh@linuxfoundation.org, kitakar@gmail.com, dan.carpenter@oracle.org Subject: Re: [RFC PATCH v3 3/9] software_node: Fix failure to hold refcount in software_node_get_next_child Message-ID: <20201021093759.GE843@valkosipuli.retiisi.org.uk> References: <20201019225903.14276-1-djrscally@gmail.com> <20201019225903.14276-4-djrscally@gmail.com> <20201020133148.GB843@valkosipuli.retiisi.org.uk> <20201021093321.GM4077@smile.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201021093321.GM4077@smile.fi.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 21, 2020 at 12:33:21PM +0300, Andy Shevchenko wrote: > On Wed, Oct 21, 2020 at 12:25:28AM +0100, Dan Scally wrote: > > On 20/10/2020 14:31, Sakari Ailus wrote: > > > On Mon, Oct 19, 2020 at 11:58:57PM +0100, Daniel Scally wrote: > > > >> + return software_node_get(&c->fwnode); > > > I believe similarly, the function should drop the reference to the previous > > > node, and not expect the caller to do this. The OF equivalent does the > > > same. > > > > I think I prefer it this way myself, since the alternative is having to > > explicitly call *_node_get() on a returned child if you want to keep it > > but also keep iterating. But I agree that it's important to take a > > consistent approach. I'll add that too; this will mean > > swnode_graph_find_next_port() and > > software_node_graph_get_next_endpoint() in patch 4 of this series will > > need changing slightly to square away their references. > > What about ACPI case? Does it square? In ACPI, we seem to assume these nodes are always there and thus don't need reference counting. -- Sakari Ailus