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=-11.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 0E5B8C433E0 for ; Thu, 4 Feb 2021 16:18:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D6E8064DEE for ; Thu, 4 Feb 2021 16:18:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237858AbhBDQSg (ORCPT ); Thu, 4 Feb 2021 11:18:36 -0500 Received: from mail.kernel.org ([198.145.29.99]:42484 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237830AbhBDQOF (ORCPT ); Thu, 4 Feb 2021 11:14:05 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7849E64E2C; Thu, 4 Feb 2021 16:13:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612455187; bh=TIfCzhCipP4xK2VKKltkiXXtzpX6perlJg4lSjRnXe4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=1bzTiaTYQTuZFj1ix7tTTc15iy/EN0h9b69uCVrD6OAz9o/zgARcpHbu12urcBJV5 fxk0iEJ8hDYtOmFGQ0wOFWCoywAujdDwd6/MlKenR1fS878B21ZB+ae302Yuuag3Fi l8AOJhTSh1POvKxeRuU5pmuUFveT6Cifvt1++AuY= Date: Thu, 4 Feb 2021 17:13:04 +0100 From: Greg Kroah-Hartman To: "Rafael J. Wysocki" Cc: Heikki Krogerus , Andy Shevchenko , Felipe Balbi , Mathias Nyman , Linux Kernel Mailing List , "open list:ULTRA-WIDEBAND (UWB) SUBSYSTEM:" Subject: Re: [PATCH v2 1/6] software node: Provide replacement for device_add_properties() Message-ID: References: <20210204141711.53775-1-heikki.krogerus@linux.intel.com> <20210204141711.53775-2-heikki.krogerus@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Feb 04, 2021 at 05:06:53PM +0100, Rafael J. Wysocki wrote: > On Thu, Feb 4, 2021 at 3:17 PM Heikki Krogerus > wrote: > > > > At the moment the function device_del() is calling > > device_remove_properties() unconditionally. That will result into the > > reference count of the software node attached to the device being > > decremented, and in most cases it will hit 0 at that point. So in > > practice device_del() will unregister the software node attached to > > the device, even if that was not the intention of the caller. Right > > now software nodes can not be reused or shared because of that. > > > > So device_del() can not unregister the software nodes unconditionally > > like that. Unfortunately some of the users of device_add_properties() > > are now relying on this behaviour. Because of that, and also in > > general, we do need a function that can offer similar behaviour where > > the lifetime of the software node is bound to the lifetime of the > > device. But it just has to be a separate function so the behaviour is > > optional. We can not remove the device_remove_properties() call from > > device_del() before we have that new function, and before we have > > replaced device_add_properties() calls with it in all the places that > > require that behaviour. > > > > This adds function device_create_managed_software_node() that can be > > used for exactly that purpose. Software nodes created with it are > > declared "managed", and separate handling for those nodes is added to > > the software node code. The reference count of the "managed" nodes is > > decremented when the device they are attached to is removed. This will > > not affect the other nodes that are not declared "managed". > > > > The function device_create_managed_software_node() has also one > > additional feature that device_add_properties() does not have. It > > allows the software nodes created with it to be part of a node > > hierarchy by taking also an optional parent node as parameter. > > > > Signed-off-by: Heikki Krogerus > > The rationale is clear now, so > > Reviewed-by: Rafael J. Wysocki > > and I'm assuming that this will be routed via the USB tree. Yes, I will do so, thanks. greg k-h