Re: [PATCH] PCI / PM: Restore PME Enable after config space restoration

From: Rafael J. Wysocki
Date: Wed Jul 12 2017 - 16:30:19 EST

On Wed, Jul 12, 2017 at 9:57 PM, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> On Wed, Jul 12, 2017 at 03:05:39AM +0200, Rafael J. Wysocki wrote:
>> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>> Commit dc15e71eefc7 (PCI / PM: Restore PME Enable if skipping wakeup
>> setup) introduced a mechanism by which the PME Enable bit can be
>> restored by pci_enable_wake() if dev->wakeup_prepared is set in
>> case it has been overwritten by PCI config space restoration.
>> However, that commit overlooked the fact that on some systems (Dell
>> XPS13 9360 in particular) the AML handling wakeup events checks PME
>> Status and PME Enable and it won't trigger a Notify() for devices
>> where those bits are not set while it is running.
>> That happens during resume from suspend-to-idle when pci_restore_state()
>> invoked by pci_pm_default_resume_early() clears PME Enable before the
>> wakeup events are processed by AML, effectively causing those wakeup
>> events to be ignored.
>> Fix this issue by restoring the PME Enable configuration right after
>> pci_restore_state() has been called instead of doing that in
>> pci_enable_wake().
>> Fixes: dc15e71eefc7 (PCI / PM: Restore PME Enable if skipping wakeup setup)
>> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Since you merged dc15e71eefc7, do you want to merge the fix as well?
> Let me know if you'd rather have me take it.

I will take this one.