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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAJZ5v0gAjB4w_jHk2=hgAypV5pF5GZxnxPoq7RrWTiJ7XPjGCQ@mail.gmail.com>
Date:   Wed, 12 Jul 2017 22:30:12 +0200
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Bjorn Helgaas <helgaas@...nel.org>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Linux PCI <linux-pci@...r.kernel.org>,
        Linux PM <linux-pm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Linux ACPI <linux-acpi@...r.kernel.org>,
        Bjorn Helgaas <bhelgaas@...gle.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: Re: [PATCH] PCI / PM: Restore PME Enable after config space restoration

On Wed, Jul 12, 2017 at 9:57 PM, Bjorn Helgaas <helgaas@...nel.org> wrote:
> On Wed, Jul 12, 2017 at 03:05:39AM +0200, Rafael J. Wysocki wrote:
>> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
>>
>> 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@...el.com>
>
> Acked-by: Bjorn Helgaas <bhelgaas@...gle.com>
>
> 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.

Thanks!