linux-kernel - Re: [RFC 1/3] PCI/PM: Fix kexec for D3cold and bridge suspending

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

Message-ID: <CAErSpo5fVbN2vD5Omc7dGJFWUccYZoCOVRF4YmXPe2Oxm81u5g@mail.gmail.com>
Date:	Mon, 17 Sep 2012 14:54:16 -0600
From:	Bjorn Helgaas <bhelgaas@...gle.com>
To:	Huang Ying <ying.huang@...el.com>
Cc:	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
	linux-pm@...r.kernel.org, "Rafael J. Wysocki" <rjw@...k.pl>,
	Eric Biederman <ebiederm@...ssion.com>,
	kexec@...ts.infradead.org
Subject: Re: [RFC 1/3] PCI/PM: Fix kexec for D3cold and bridge suspending

+cc Eric and kexec list

On Mon, Sep 17, 2012 at 2:54 AM, Huang Ying <ying.huang@...el.com> wrote:
> If PCI devices are put into D3cold before kexec, because the
> configuration registers of PCI devices in D3cold are not accessible.
>
> And if PCI bridges are put into low power state before kexec,
> configuration registers of PCI devices underneath the PCI bridges are
> not accessible too.
>
> These will make some PCI devices can not be scanned after kexec, so
> resume the PCI devices in D3cold or PCI bridges in low power state
> before kexec.

Don't we need to resume the device even without the kexec issue?  And
even if it's in D1 or D2?

It looks to me like pci_msi_shutdown() (and probably drv->shutdown())
depend on the device being in D0.

> Signed-off-by: Huang Ying <ying.huang@...el.com>
> ---
>  drivers/pci/pci-driver.c |    4 ++++
>  1 file changed, 4 insertions(+)
>
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -421,6 +421,10 @@ static void pci_device_shutdown(struct d
>         struct pci_dev *pci_dev = to_pci_dev(dev);
>         struct pci_driver *drv = pci_dev->driver;
>
> +       /* Resume bridges and devices in D3cold for kexec to work properly */
> +       if (pci_dev->current_state == PCI_D3cold || pci_dev->subordinate)
> +               pm_runtime_resume(dev);
> +
>         if (drv && drv->shutdown)
>                 drv->shutdown(pci_dev);
>         pci_msi_shutdown(pci_dev);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/