From: Alan Stern Date: Fri, 21 Oct 2016 20:45:38 +0000 (-0400) Subject: PCI: Check for PME in targeted sleep state X-Git-Tag: v3.2.87~194 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=45eb84690cc1c2ea0b9e11ab968f7d2642617083 PCI: Check for PME in targeted sleep state commit 6496ebd7edf446fccf8266a1a70ffcb64252593e 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: Pierre de Villemereuil Tested-by: Pierre de Villemereuil Signed-off-by: Alan Stern Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki CC: Lukas Wunner Signed-off-by: Ben Hutchings --- diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4c3a9e9bf289..6b72e4a0b1b8 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1763,6 +1763,10 @@ 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;