From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1753221AbeBFSCJ convert rfc822-to-8bit (ORCPT <rfc822;w@1wt.eu>);
        Tue, 6 Feb 2018 13:02:09 -0500
Received: from cloudserver094114.home.pl ([79.96.170.134]:62521 "EHLO
        cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1753144AbeBFSBy (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 6 Feb 2018 13:01:54 -0500
From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Ville =?ISO-8859-1?Q?Syrj=E4l=E4?= <ville.syrjala@linux.intel.com>
Cc: Linux PM <linux-pm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>
Subject: Re: [PATCH] Revert "cpuidle: Make drivers initialize polling state"
Date: Tue, 06 Feb 2018 19:00:12 +0100
Message-ID: <2461225.Wj8P4Aemd9@aspire.rjw.lan>
In-Reply-To: <20180206163134.GO5453@intel.com>
References: <20180122162747.19103-1-ville.syrjala@linux.intel.com> <36158666.hf5grRdGNf@aspire.rjw.lan> <20180206163134.GO5453@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8BIT
Content-Type: text/plain; charset="iso-8859-1"
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tuesday, February 6, 2018 5:31:34 PM CET Ville Syrjälä wrote:
> On Mon, Feb 05, 2018 at 06:56:31PM +0100, Rafael J. Wysocki wrote:
> > On Monday, February 5, 2018 3:04:45 PM CET Ville Syrjälä wrote:
> > > On Sun, Feb 04, 2018 at 10:18:07AM +0100, Rafael J. Wysocki wrote:
> > > > On Sun, Feb 4, 2018 at 10:12 AM, Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > > > On Mon, Jan 22, 2018 at 5:27 PM, Ville Syrjala
> > > > > <ville.syrjala@linux.intel.com> wrote:
> > > > >> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > >>
> > > > >> This reverts commit 1b39e3f813b4685c7a30ae964d5529a1b0e3a286.
> > > > >>
> > > > >> Makes my P3 machine oops somewhere in cpuidle. I suspect
> > > > >> CONFIG_ACPI=n may have something to do with this.
> > > > >
> > > > > And if you don't do CONFIG_ACPI=n, does it still oops?
> > > 
> > > Don't think I actually tried that. I can give it a whirl tonight.
> > > 
> > > I think this machine should actually have ACPI, but it inherited
> > > the .config from a P2 machine that did not. Apparently I was too
> > > lazy to change .config when I swapped in the "new" machine.
> > 
> > I guess it would work, but never mind.
> > 
> > > > >
> > > > > Anyway, there are later changes depending on this one, so reverting it
> > > > > won't work in general.
> > > > >
> > > > > Let me look deeper at this.
> > > > 
> > > > What's there in /sys/devices/system/cpu/cpuidle/current_driver on your
> > > > system with the problematic commit reverted?
> > > 
> > > # cat /sys/devices/system/cpu/cpuidle/current_driver
> > > apm_idle
> > 
> > That is the key bit: I overlooked this little fellow.
> > 
> > Does the below (untested here) help?
> > 
> > ---
> >  arch/x86/kernel/apm_32.c |    1 +
> >  1 file changed, 1 insertion(+)
> > 
> > Index: linux-pm/arch/x86/kernel/apm_32.c
> > ===================================================================
> > --- linux-pm.orig/arch/x86/kernel/apm_32.c
> > +++ linux-pm/arch/x86/kernel/apm_32.c
> > @@ -2389,6 +2389,7 @@ static int __init apm_init(void)
> >  	if (HZ != 100)
> >  		idle_period = (idle_period * HZ) / 100;
> >  	if (idle_threshold < 100) {
> > +		cpuidle_poll_state_init(&apm_idle_driver);
> >  		if (!cpuidle_register_driver(&apm_idle_driver))
> >  			if (cpuidle_register_device(&apm_cpuidle_device))
> >  				cpuidle_unregister_driver(&apm_idle_driver);
> 
> Yep, this works. Thanks.
> 
> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Thanks!

Let me respin it with a changelog/tags etc