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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 C8DBEC282C4 for ; Mon, 4 Feb 2019 15:37:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 955D620823 for ; Mon, 4 Feb 2019 15:37:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729090AbfBDPhf (ORCPT ); Mon, 4 Feb 2019 10:37:35 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:57284 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726926AbfBDPhf (ORCPT ); Mon, 4 Feb 2019 10:37:35 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 755CF80D; Mon, 4 Feb 2019 07:37:34 -0800 (PST) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CC22E3F71E; Mon, 4 Feb 2019 07:37:32 -0800 (PST) Date: Mon, 4 Feb 2019 15:37:20 +0000 From: Sudeep Holla To: "Rafael J. Wysocki" Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Jisheng Zhang , Steve Longerbeam , Eugeniu Rosca , Joshua Frkuska , Sudeep Holla , Greg Kroah-Hartman Subject: Re: [RFC PATCH] drivers core: cpu: add hotplug callback to update cpu_dev state to resumed Message-ID: <20190204153720.GA24131@e107155-lin> References: <20190125130701.GA855@vmlxhi-102.adit-jv.com> <20190125150906.27614-1-sudeep.holla@arm.com> <2397404.eE4apdlqQK@aspire.rjw.lan> <20190131160559.GA32759@e107155-lin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190131160559.GA32759@e107155-lin> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 31, 2019 at 04:05:59PM +0000, Sudeep Holla wrote: > On Thu, Jan 31, 2019 at 12:48:49AM +0100, Rafael J. Wysocki wrote: > > On Friday, January 25, 2019 4:09:06 PM CET Sudeep Holla wrote: > > > The sysfs for the cpu caches are managed by adding devices with cpu > > > as the parent in cpu_device_create() when secondary cpu is brought > > > onlin. Generally when the secondary CPUs are hotplugged back is as part > > > of resume from suspend-to-ram, we call cpu_device_create() from the cpu > > > hotplug state machine while the cpu device associated with that CPU is > > > not yet ready to be resumed as the device_resume() call happens bit later. > > > It's not really needed to set the flag is_prepared for cpu devices are > > > they are mostly pseudo device and hotplug framework deals with state > > > machine and not managed through the cpu device. > > > > > > This often results in annoying warning when resuming: > > > Enabling non-boot CPUs ... > > > CPU1: Booted secondary processor > > > cache: parent cpu1 should not be sleeping > > > CPU1 is up > > > CPU2: Booted secondary processor > > > cache: parent cpu2 should not be sleeping > > > CPU2 is up > > > .... and so on. > > > > > > Just fix the warning by updating the device state quite early. > > > > > > Cc: "Rafael J. Wysocki" > > > Reported-by: Jisheng Zhang > > > Reported-by: Steve Longerbeam > > > Reported-by: Eugeniu Rosca > > > Signed-off-by: Sudeep Holla > > > --- > > > drivers/base/cpu.c | 20 +++++++++++++++++++- > > > include/linux/cpuhotplug.h | 1 + > > > 2 files changed, 20 insertions(+), 1 deletion(-) > > > > > > Hi Rafael, > > > > > > This is getting reported for quite some time. Let me know if you have > > > better solution to fix this harmless yet annoying warnings during system > > > resume. > > > > I'd rather have a flag in struct dev_pm_info that will cause the message to > > be suppressed if set. > > > > It could be used for other purposes too then in princple (like skipping the > > creation of empty "power" attr groups in sysfs for devices that don't > > need them etc.). > > > Thanks for the suggestion. I did quick hack and came up with something > below. I wanted to run through you once before I materialise it into > a formal patch to check if I understood your suggestion correctly. > We can move no_pm_required outside dev_pm_info struct and rename with > any better names. > Sorry for the nag, since the title has RFC, thought there are chances of this getting lost. Let me know if the below idea aligns with your suggestion ? Regards, Sudeep > -->8 > > diff --git i/drivers/base/cpu.c w/drivers/base/cpu.c > index eb9443d5bae1..b61f9772ed33 100644 > --- i/drivers/base/cpu.c > +++ w/drivers/base/cpu.c > @@ -379,6 +379,7 @@ int register_cpu(struct cpu *cpu, int num) > cpu->dev.bus->uevent = cpu_uevent; > #endif > cpu->dev.groups = common_cpu_attr_groups; > + cpu->dev.power.no_pm_required = true; > if (cpu->hotpluggable) > cpu->dev.groups = hotplugable_cpu_attr_groups; > error = device_register(&cpu->dev); > @@ -427,6 +428,7 @@ __cpu_device_create(struct device *parent, void *drvdata, > dev->parent = parent; > dev->groups = groups; > dev->release = device_create_release; > + dev->power.no_pm_required = true; > dev_set_drvdata(dev, drvdata); > > retval = kobject_set_name_vargs(&dev->kobj, fmt, args); > diff --git i/drivers/base/power/main.c w/drivers/base/power/main.c > index 0992e67e862b..ed1b133f73db 100644 > --- i/drivers/base/power/main.c > +++ w/drivers/base/power/main.c > @@ -124,6 +124,8 @@ void device_pm_unlock(void) > */ > void device_pm_add(struct device *dev) > { > + if (dev->power.no_pm_required) > + return; > pr_debug("PM: Adding info for %s:%s\n", > dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); > device_pm_check_callbacks(dev); > @@ -142,6 +144,8 @@ void device_pm_add(struct device *dev) > */ > void device_pm_remove(struct device *dev) > { > + if (dev->power.no_pm_required) > + return; > pr_debug("PM: Removing info for %s:%s\n", > dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); > complete_all(&dev->power.completion); > diff --git i/drivers/base/power/sysfs.c w/drivers/base/power/sysfs.c > index d713738ce796..54c1bfec396e 100644 > --- i/drivers/base/power/sysfs.c > +++ w/drivers/base/power/sysfs.c > @@ -648,6 +648,9 @@ int dpm_sysfs_add(struct device *dev) > { > int rc; > > + if (dev->power.no_pm_required) > + return 0; > + > rc = sysfs_create_group(&dev->kobj, &pm_attr_group); > if (rc) > return rc; > diff --git i/include/linux/pm.h w/include/linux/pm.h > index 0bd9de116826..300ab9f0b858 100644 > --- i/include/linux/pm.h > +++ w/include/linux/pm.h > @@ -592,6 +592,7 @@ struct dev_pm_info { > bool is_suspended:1; /* Ditto */ > bool is_noirq_suspended:1; > bool is_late_suspended:1; > + bool no_pm_required:1; > bool early_init:1; /* Owned by the PM core */ > bool direct_complete:1; /* Owned by the PM core */ > u32 driver_flags;