From 6496ebd7edf446fccf8266a1a70ffcb64252593e Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 21 Oct 2016 16:45:38 -0400 Subject: [PATCH] PCI: Check for PME in targeted sleep state 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: Pierre de Villemereuil Tested-by: Pierre de Villemereuil Signed-off-by: Alan Stern Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki CC: stable@vger.kernel.org CC: Lukas Wunner --- drivers/pci/pci.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index ba34907538f6..eda6a7cf0e54 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2106,6 +2106,10 @@ 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;