Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81A52C433F5 for ; Tue, 16 Nov 2021 16:32:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68BB561266 for ; Tue, 16 Nov 2021 16:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233614AbhKPQfY (ORCPT ); Tue, 16 Nov 2021 11:35:24 -0500 Received: from mail-oo1-f48.google.com ([209.85.161.48]:39676 "EHLO mail-oo1-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233425AbhKPQdE (ORCPT ); Tue, 16 Nov 2021 11:33:04 -0500 Received: by mail-oo1-f48.google.com with SMTP id d1-20020a4a3c01000000b002c2612c8e1eso7412561ooa.6; Tue, 16 Nov 2021 08:30:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WDrq+QOnZFTPGeBGIaTOzJl6i+SxZ4J4MSSRm1zXWEo=; b=pzUVTBKPpMUzSEyuoo8RXlXB1b3e7ZX3yxDmfEnHb32yxU9qnpKCiry+85Cn1Iva7k EpgMbQiEClb1ntD9HKU41R+/4BnScyFJVTDN40juj2Tf7LBYCJTjMfX1+fXMMDDhO9De iDkvmXZPsJW4mBPBbNbBoZjthTkoxUBs744guoo1OPngy8OQs35sBghviwvQutQUrP27 VuNwDSuys3b8Yh1V88YuvzTlzdvAjvoq+l0SfhF3LCzCDKu0/oSURdI6pR7ERZH9NJ9g eqZd4ZYZsEgm4faNwbl1ibEl7CjNeHPw32m/hzqWcthCd2qr2tglwApdIqMho5Iz9Uxr gwSA== X-Gm-Message-State: AOAM532nHESU9wmnBLEPHOpmJef6ChJJMUb+3nUaSQP9B9T+83MQmmni 5TIQ7d+CtNcUzj/8vDwNkaBumtri+bcWU02V3E8= X-Google-Smtp-Source: ABdhPJxK/62djEfWaXqQrqza5crsAmOwUIaEHqlghK4v2HJzDZB/TIcs7/cdigkhRN0w2Xl4J44nQng2/aBhY8d7cE0= X-Received: by 2002:a4a:ead8:: with SMTP id s24mr4437160ooh.89.1637080207075; Tue, 16 Nov 2021 08:30:07 -0800 (PST) MIME-Version: 1.0 References: <20211101200346.16466-1-quic_qiancai@quicinc.com> <52df4a97-1132-d594-0180-132d0ca714d5@quicinc.com> In-Reply-To: From: "Rafael J. Wysocki" Date: Tue, 16 Nov 2021 17:29:56 +0100 Message-ID: Subject: Re: [RFC PATCH] software node: Skip duplicated software_node sysfs To: Qian Cai Cc: Andy Shevchenko , "Rafael J. Wysocki" , Andy Shevchenko , Heikki Krogerus , Greg Kroah-Hartman , Laurentiu Tudor , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 16, 2021 at 4:54 AM Qian Cai wrote: > > On Fri, Nov 05, 2021 at 09:39:42PM +0200, Andy Shevchenko wrote: > > > Anyway, what's the "upper layer"? Is that "struct device" or "struct > > > swnode"? I suppose you meant: > > > > struct device here. > > > > > - Remove "secondary" field from "struct fwnode_handle". > > > - Replace "fwnode" from "upper layer" with > > > "struct list_head fwnode_head;". > > > - Modify all functions in "software_node_ops" to use "fwnode_head". > > > > > > Is that correct? > > > > Yes. > > > > It might be a bit complicated taking into account how much fwnode is > > spreaded in the kernel... Basically, you need to fix all direct > > accesses to the dev->fwnode first. > > Besides that you need to check that fwnode, which is used out of the > > device scope, like in IRQ domains, doesn't use secondary pointer(s). > > > > This nevertheless adds a lot of flexibility and we may add whatever > > type of fwnodes and mix them together. > > Okay, here is my plan until someone still has an idea to avoid a > redesign. > > Frist, fixes all dev->fwnode / dev.fwnode to use dev_fwnode(). This > could be a standalone tree-wide patchset going out to avoid > heavy-lifting later. > > Then, we can create another patchset on top. I have audited > "irq_domain" but not seen any "secondary" leakage. Struct > "cht_int33fe_data" does have some need to fix. > > Rename set_secondary_fwnode() to insert_secondary_fwnode(). Fix things > in drivers/base/core.c, swnode.c etc to use the new fwnode_head and > anything I can't think of right now. > > Since we will have multiple "software_node" (secondary fwnode:s) for a > single "device". What would be the usual way to deal with a > linked-list in the sysfs? I can think of just let "software_node" > become a directory to host a list of symlinks named from > swnode->id. Thoughts? Note that one pointer dereference in ACPI_COMPANION() is enough.