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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3189EC7619A for ; Wed, 22 Mar 2023 09:04:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230044AbjCVJEv (ORCPT ); Wed, 22 Mar 2023 05:04:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229487AbjCVJEs (ORCPT ); Wed, 22 Mar 2023 05:04:48 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B9B621A35; Wed, 22 Mar 2023 02:04:46 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id F3BCAB818F9; Wed, 22 Mar 2023 09:04:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43D7DC433EF; Wed, 22 Mar 2023 09:04:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1679475883; bh=oz2PN3tKGuhTQo56pqzJbIezCGcNGA9n5ON2iB/N3K4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PMEqf3qUQsh0QDJZ0PJY25wqSIlbuILMOKwl8D2bTsqPCIHol9i51F3HlRrkxcAa9 HyuXIIxpj09P1x1q7PlUgmnV8b1QGANM/vllb2lLiNeC4kP9BdDwZP3HB8K3NQHijf BuHuIrMnv3JnVn9rMN6wp7qxs0qYtS3toZTUGUtU= Date: Wed, 22 Mar 2023 10:04:40 +0100 From: Greg Kroah-Hartman To: "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org, Daniel Lezcano , linux-pm@vger.kernel.org Subject: Re: [PATCH 06/36] cpuidle: move to use bus_get_dev_root() Message-ID: References: <20230313182918.1312597-1-gregkh@linuxfoundation.org> <20230313182918.1312597-6-gregkh@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 13, 2023 at 07:58:02PM +0100, Rafael J. Wysocki wrote: > On Mon, Mar 13, 2023 at 7:30 PM Greg Kroah-Hartman > wrote: > > > > Direct access to the struct bus_type dev_root pointer is going away soon > > so replace that with a call to bus_get_dev_root() instead, which is what > > it is there for. > > > > This allows us to clean up the cpuidle_add_interface() call a bit as it > > was only called in one place, with the same argument so just put that > > into the function itself. Note that cpuidle_remove_interface() should > > also probably be removed in the future as there are no callers of it for > > some reason. > > > > Cc: "Rafael J. Wysocki" > > Cc: Daniel Lezcano > > Cc: linux-pm@vger.kernel.org > > Signed-off-by: Greg Kroah-Hartman > > --- > > Note, this is a patch that is a prepatory cleanup as part of a larger > > series of patches that is working on resolving some old driver core > > design mistakes. It will build and apply cleanly on top of 6.3-rc2 on > > its own, but I'd prefer if I could take it through my driver-core tree > > so that the driver core changes can be taken through there for 6.4-rc1. > > > > drivers/cpuidle/cpuidle.c | 2 +- > > drivers/cpuidle/cpuidle.h | 2 +- > > drivers/cpuidle/sysfs.c | 12 +++++++++--- > > 3 files changed, 11 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > > index 0b00f21cefe3..8e929f6602ce 100644 > > --- a/drivers/cpuidle/cpuidle.c > > +++ b/drivers/cpuidle/cpuidle.c > > @@ -808,7 +808,7 @@ static int __init cpuidle_init(void) > > if (cpuidle_disabled()) > > return -ENODEV; > > > > - return cpuidle_add_interface(cpu_subsys.dev_root); > > + return cpuidle_add_interface(); > > } > > > > module_param(off, int, 0444); > > diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h > > index 9f336af17fa6..52701d9588f1 100644 > > --- a/drivers/cpuidle/cpuidle.h > > +++ b/drivers/cpuidle/cpuidle.h > > @@ -30,7 +30,7 @@ extern int cpuidle_switch_governor(struct cpuidle_governor *gov); > > > > struct device; > > > > -extern int cpuidle_add_interface(struct device *dev); > > +extern int cpuidle_add_interface(void); > > extern void cpuidle_remove_interface(struct device *dev); > > extern int cpuidle_add_device_sysfs(struct cpuidle_device *device); > > extern void cpuidle_remove_device_sysfs(struct cpuidle_device *device); > > diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c > > index 48948b171749..84e4946f1072 100644 > > --- a/drivers/cpuidle/sysfs.c > > +++ b/drivers/cpuidle/sysfs.c > > @@ -119,11 +119,17 @@ static struct attribute_group cpuidle_attr_group = { > > > > /** > > * cpuidle_add_interface - add CPU global sysfs attributes > > - * @dev: the target device > > */ > > -int cpuidle_add_interface(struct device *dev) > > +int cpuidle_add_interface(void) > > { > > - return sysfs_create_group(&dev->kobj, &cpuidle_attr_group); > > + struct device *dev_root = bus_get_dev_root(&cpu_subsys); > > + int retval = -EINVAL; > > + > > + if (dev_root) { > > + retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group); > > + put_device(dev_root); > > + } > > + return retval; > > I would prefer > > if (!dev_root) > return -EINVAL; > > retval = sysfs_create_group(&dev_root->kobj, &cpuidle_attr_group); > put_device(dev_root); > return retval; > > assuming that successful group creation will bump up the reference > counter of dev_root. That is correct. I'll respin this with this change in it now, thanks for the review! greg k-h