PCI / ACPI PM: Propagate wake-up enable for devices w/o ACPI support

Some PCI devices (not PCI Express), like PCI add-on cards, can
generate PME#, but they don't have any special platform wake-up
support.  For this reason, even if they generate PME# to wake up the
system from a sleep state, wake-up events are not generated by the
platform.

It turns out that, at least on some systems, PCI bridges and the PCI
host bridge have ACPI GPEs associated with them that, if enabled to
generate wake-up events, allow the system to wake up if one of the
add-on devices asserts PME# while the system is in a sleep state.
Following this observation, if a PCI device without direct ACPI
wake-up support is prepared to wake up the system during a transition
into a sleep state (eg. suspend to RAM), try to configure the bridges
on the path from the device to the root bridge to wake-up the system.

Reviewed-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index ab889becd3f3d56bf56ba66f2caf25cb5433274c..feece693d773be300959d1bb1f8b58c975d05e79 100644 (file)
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -691,7 +691,7 @@ int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
        struct acpi_device *adev;
        int error;
 
-       if (!device_may_wakeup(dev))
+       if (!device_can_wakeup(dev))
                return -EINVAL;
 
        handle = DEVICE_ACPI_HANDLE(dev);

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 0bddd787490d39b4e3e511d6eec5d7ad8547b8a9..33317df47699d0a69f18b6970583fb23b246f7f9 100644 (file)
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -109,10 +109,32 @@ static bool acpi_pci_can_wakeup(struct pci_dev *dev)
        return handle ? acpi_bus_can_wakeup(handle) : false;
 }
 
+static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
+{
+       while (bus->parent) {
+               struct pci_dev *bridge = bus->self;
+               int ret;
+
+               ret = acpi_pm_device_sleep_wake(&bridge->dev, enable);
+               if (!ret || bridge->is_pcie)
+                       return;
+               bus = bus->parent;
+       }
+
+       /* We have reached the root bus. */
+       if (bus->bridge)
+               acpi_pm_device_sleep_wake(bus->bridge, enable);
+}
+
 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 {
-       return acpi_pci_can_wakeup(dev) ?
-               acpi_pm_device_sleep_wake(&dev->dev, enable) : 0;
+       if (acpi_pci_can_wakeup(dev))
+               return acpi_pm_device_sleep_wake(&dev->dev, enable);
+
+       if (!dev->is_pcie)
+               acpi_pci_propagate_wakeup_enable(dev->bus, enable);
+
+       return 0;
 }
 
 static struct pci_platform_pm_ops acpi_pci_platform_pm = {