From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pierre de Villemereuil , Alan Stern , Bjorn Helgaas , "Rafael J. Wysocki" , Lukas Wunner Subject: [PATCH 4.4 50/58] PCI: Check for PME in targeted sleep state Date: Fri, 6 Jan 2017 22:44:35 +0100 Message-Id: <20170106213908.880640944@linuxfoundation.org> In-Reply-To: <20170106213906.290654840@linuxfoundation.org> References: <20170106213906.290654840@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern 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: Greg Kroah-Hartman --- drivers/pci/pci.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2043,6 +2043,10 @@ 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;