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From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Fri, 14 Sep 2018 10:11:25 +0200
Message-ID: <CAJZ5v0gzacxkV+6gbY+paq6=h71KWpRM4pG5ko-Fu3ROdJ2AXQ@mail.gmail.com>
Subject: Re: [PATCH v2 01/10] PCI: Do not skip power managed bridges in pci_enable_wake()
To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Len Brown <lenb@kernel.org>, Lukas Wunner <lukas@wunner.de>,
        Keith Busch <keith.busch@intel.com>,
        "Raj, Ashok" <ashok.raj@intel.com>,
        Mario Limonciello <Mario.Limonciello@dell.com>,
        Anthony Wong <anthony.wong@canonical.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Sakari Ailus <sakari.ailus@iki.fi>,
        Linux PCI <linux-pci@vger.kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>
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On Fri, Sep 14, 2018 at 10:07 AM Mika Westerberg
<mika.westerberg@linux.intel.com> wrote:
>
> On Thu, Sep 13, 2018 at 04:33:39PM +0200, Rafael J. Wysocki wrote:
> > On Thursday, September 13, 2018 4:33:13 PM CEST Mika Westerberg wrote:
> > > Commit baecc470d5fd ("PCI / PM: Skip bridges in pci_enable_wake()")
> > > changed pci_enable_wake() so that all bridges are skipped when wakeup is
> > > enabled (or disabled) with the reasoning that bridges can only signal
> > > wakeup on behalf of their subordinate devices.
> > >
> > > However, there are bridges that can signal wakeup itself. For example
> > > PCIe downstream and root ports supporting hotplug may signal wakeup upon
> > > hotplug event.
> > >
> > > For this reason change pci_enable_wake() so that it skips all bridges
> > > except those that we power manage (->bridge_d3 is set). Those are the
> > > ones that can go into low power states and may need to signal wakeup.
> > >
> > > Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> > > ---
> > >  drivers/pci/pci.c | 9 ++++++---
> > >  1 file changed, 6 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > > index 29ff9619b5fa..1af6f1887986 100644
> > > --- a/drivers/pci/pci.c
> > > +++ b/drivers/pci/pci.c
> > > @@ -2133,10 +2133,13 @@ static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable
> > >     int ret = 0;
> > >
> > >     /*
> > > -    * Bridges can only signal wakeup on behalf of subordinate devices,
> > > -    * but that is set up elsewhere, so skip them.
> > > +    * Bridges that are not power-manageable directly only signal
> > > +    * wakeup on behalf of subordinate devices which is set up
> > > +    * elsewhere, so skip them. However, bridges that are
> > > +    * power-manageable may signal wakeup for themselves (for example,
> > > +    * on a hotplug event) and they need to be covered here.
> > >      */
> > > -   if (pci_has_subordinate(dev))
> > > +   if (!pci_power_manageable(dev))
> > >             return 0;
> > >
> > >     /* Don't do the same thing twice in a row for one device. */
> > >
> >
> > Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Thanks!
>
> For some reason this patch never hit the mailing lists (others did).
> Since you kept the whole context people should still be able to review
> it. I can resend this patch as well.

You may need to resend for Patchwork to pick it up, though.  Depends
on Bjorn I suppose.