Re: [PATCH] PCI / ACPI: Always resume devices on ACPI wakeup notifications

Rafael J. Wysocki
2013-03-25T22:27:35Z

On Monday, March 25, 2013 09:45:51 AM Sarah Sharp wrote:
> On Sat, Mar 23, 2013 at 03:33:03PM +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > It turns out that _Lxx control methods provided by some BIOSes clear
> > the PME Status bit of PCI devices they handle, which means that
> > pci_acpi_wake_dev() cannot really use that bit to check whether or
> > not the device has signalled wakeup.
> >
> > For this reason, make pci_acpi_wake_dev() always attempt to resume
> > the device it is called for regardless of the device's PME Status bit
> > value (that bit still has to be cleared if set at this point,
> > though).
> >
> > Reported-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Should this be marked for stable? I had this issue on 3.7 and 3.8 as
> well.

Yes, it probably should, but that's the maintainer's call.

Thanks,
Rafael

> > ---
> > drivers/pci/pci-acpi.c | 15 ++++++++-------
> > 1 file changed, 8 insertions(+), 7 deletions(-)
> >
> > Index: linux-pm/drivers/pci/pci-acpi.c
> > ===================================================================
> > --- linux-pm.orig/drivers/pci/pci-acpi.c
> > +++ linux-pm/drivers/pci/pci-acpi.c
> > @@ -53,14 +53,15 @@ static void pci_acpi_wake_dev(acpi_handl
> > return;
> > }
> >
> > - if (!pci_dev->pm_cap || !pci_dev->pme_support
> > - || pci_check_pme_status(pci_dev)) {
> > - if (pci_dev->pme_poll)
> > - pci_dev->pme_poll = false;
> > + /* Clear PME Status if set. */
> > + if (pci_dev->pme_support)
> > + pci_check_pme_status(pci_dev);
> >
> > - pci_wakeup_event(pci_dev);
> > - pm_runtime_resume(&pci_dev->dev);
> > - }
> > + if (pci_dev->pme_poll)
> > + pci_dev->pme_poll = false;
> > +
> > + pci_wakeup_event(pci_dev);
> > + pm_runtime_resume(&pci_dev->dev);
> >
> > if (pci_dev->subordinate)
> > pci_pme_wakeup_bus(pci_dev->subordinate);
> >
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.