From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Rafael J. Wysocki" <rjw@sisk.pl>
Subject: Re: [PATCH 6/8] PCI ACPI: Rework PCI handling of wake-up
Date: Fri, 27 Jun 2008 17:12:17 +0200
Message-ID: <200806271712.18694.rjw@sisk.pl>
References: <200806270022.24496.rjw@sisk.pl> <1214532498.26388.2.camel@sli10-desk.sh.intel.com> <200806271526.46932.rjw@sisk.pl>
Mime-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-15"
Content-Transfer-Encoding: 7bit
Return-path: <linux-acpi-owner@vger.kernel.org>
Received: from ogre.sisk.pl ([217.79.144.158]:37381 "EHLO ogre.sisk.pl"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1758029AbYF0PKs (ORCPT <rfc822;linux-acpi@vger.kernel.org>);
	Fri, 27 Jun 2008 11:10:48 -0400
In-Reply-To: <200806271526.46932.rjw@sisk.pl>
Content-Disposition: inline
Sender: linux-acpi-owner@vger.kernel.org
List-Id: linux-acpi@vger.kernel.org
To: Shaohua Li <shaohua.li@intel.com>
Cc: ACPI Devel Maling List <linux-acpi@vger.kernel.org>, Alan Stern <stern@rowland.harvard.edu>, Jesse Barnes <jbarnes@virtuousgeek.org>, Len Brown <lenb@kernel.org>, pm list <linux-pm@lists.linux-foundation.org>, "Zhang, Rui" <rui.zhang@intel.com>, "Zhao, Yakui" <yakui.zhao@intel.com>

On Friday, 27 of June 2008, Rafael J. Wysocki wrote:
> On Friday, 27 of June 2008, Shaohua Li wrote:
> > On Fri, 2008-06-27 at 06:28 +0800, Rafael J. Wysocki wrote:
> [--snip--]
> > > +
> > > +       if (pmc & PCI_PM_CAP_PME_MASK) {
> > > +               dev_printk(KERN_INFO, &dev->dev,
> > > +                       "PME# supported from%s%s%s%s%s\n",
> > > +                       (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
> > > +                       (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
> > > +                       (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
> > > +                       (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
> > > +                       (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" :
> > > "");
> > > +               /*
> > > +                * Make device's PM flags reflect the wake-up
> > > capability, but
> > > +                * let the user space enable it to wake up the system
> > > as needed.
> > > +                */
> > > +               device_set_wakeup_capable(&dev->dev, true);
> > > +               device_set_wakeup_enable(&dev->dev, false);
> > > +               /* Disable the PME# generation functionality */
> > > +               pci_pme_active(dev, pm, false);
> > > +       }
> > >  }
> > It appears a lot of drivers will call device_init_wakeup(dev, 1)
> > regardless if userspace enable wakeup for the device. Will you fix the
> > drivers?
> 
> Either fix the drivers, or change device_init_wakeup() so that it doesn't
> set power.should_wakeup to the same value as power.can_wakeup, which IMO is
> a mistake.
> 
> Perhaps it's better to drop device_init_wakeup() altogether.

Note, however, that in any case this will only change the default from
'wake-up enabled' to 'wake-up disabled' and the user space will be able to
change the value later on anyway.

That said, setting power.can_wakeup for devices that in fact can't wake up is
plain wrong and the drivers that do such things will have to be fixed.

Thanks,
Rafael