On Friday, October 21, 2016 04:45:38 PM Alan Stern wrote:
> One some systems, the firmware does not allow certain PCI devices to
> be put in deep D-states. This can cause problems for wakeup
> signalling, if the device does not support PME# in the deepest allowed
> suspend state. For example, Pierre reports that on his system, ACPI
> does not permit his xHCI host controller to go into D3 during runtime
> suspend -- but D3 is the only state in which the controller can generate
> PME# signals. As a result, the controller goes into runtime suspend
> but never wakes up, so it doesn't work properly. USB devices plugged
> into the controller are never detected.
>
> If the device relies on PME# for wakeup signals but is not capable of
> generating PME# in the target state, the PCI core should accurately
> report that it cannot do wakeup from runtime suspend. This patch
> modifies the pci_dev_run_wake() routine to add this check.
>
> Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> CC: Lukas Wunner <lukas@xxxxxxxxx>
> Reported-by: Pierre de Villemereuil <flyos@xxxxxxxxxx>
> Tested-by: Pierre de Villemereuil <flyos@xxxxxxxxxx>
> CC: <stable@xxxxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
>
> [as1814]
>
>
> drivers/pci/pci.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> Index: usb-4.x/drivers/pci/pci.c
> ===================================================================
> --- usb-4.x.orig/drivers/pci/pci.c
> +++ usb-4.x/drivers/pci/pci.c
> @@ -2064,6 +2064,10 @@ bool pci_dev_run_wake(struct pci_dev *de
> if (!dev->pme_support)
> return false;
>
> + /* PME-capable in principle, but not from the intended sleep state */
> + if (!pci_pme_capable(dev, pci_target_state(dev)))
> + return false;
> +
> while (bus->parent) {
> struct pci_dev *bridge = bus->self;
>
>
> --
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--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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