Commit edfe6a79 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman

PCI: Check for PME in targeted sleep state

commit 6496ebd7 upstream.

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.
Reported-by: default avatarPierre de Villemereuil <flyos@mailoo.org>
Tested-by: default avatarPierre de Villemereuil <flyos@mailoo.org>
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: Lukas Wunner <lukas@wunner.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8db00756
......@@ -2043,6 +2043,10 @@ bool pci_dev_run_wake(struct pci_dev *dev)
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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