1 files changed, 56 insertions, 1 deletions

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 8f75ba068d45..79c8e955a0ab 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -519,6 +519,46 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 	return PCI_POWER_ERROR;
 }
 
+static struct acpi_device *acpi_pci_find_companion(struct device *dev);
+
+static bool acpi_pci_bridge_d3(struct pci_dev *dev)
+{
+	const struct fwnode_handle *fwnode;
+	struct acpi_device *adev;
+	struct pci_dev *root;
+	u8 val;
+
+	if (!dev->is_hotplug_bridge)
+		return false;
+
+	/*
+	 * Look for a special _DSD property for the root port and if it
+	 * is set we know the hierarchy behind it supports D3 just fine.
+	 */
+	root = pci_find_pcie_root_port(dev);
+	if (!root)
+		return false;
+
+	adev = ACPI_COMPANION(&root->dev);
+	if (root == dev) {
+		/*
+		 * It is possible that the ACPI companion is not yet bound
+		 * for the root port so look it up manually here.
+		 */
+		if (!adev && !pci_dev_is_added(root))
+			adev = acpi_pci_find_companion(&root->dev);
+	}
+
+	if (!adev)
+		return false;
+
+	fwnode = acpi_fwnode_handle(adev);
+	if (fwnode_property_read_u8(fwnode, "HotPlugSupportInD3", &val))
+		return false;
+
+	return val == 1;
+}
+
 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 {
 	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
@@ -635,6 +675,7 @@ static bool acpi_pci_need_resume(struct pci_dev *dev)
 }
 
 static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
+	.bridge_d3 = acpi_pci_bridge_d3,
 	.is_manageable = acpi_pci_power_manageable,
 	.set_state = acpi_pci_set_power_state,
 	.get_state = acpi_pci_get_power_state,
@@ -767,19 +808,33 @@ static void pci_acpi_setup(struct device *dev)
 		return;
 
 	device_set_wakeup_capable(dev, true);
+	/*
+	 * For bridges that can do D3 we enable wake automatically (as
+	 * we do for the power management itself in that case). The
+	 * reason is that the bridge may have additional methods such as
+	 * _DSW that need to be called.
+	 */
+	if (pci_dev->bridge_d3)
+		device_wakeup_enable(dev);
+
 	acpi_pci_wakeup(pci_dev, false);
 }
 
 static void pci_acpi_cleanup(struct device *dev)
 {
 	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct pci_dev *pci_dev = to_pci_dev(dev);
 
 	if (!adev)
 		return;
 
 	pci_acpi_remove_pm_notifier(adev);
-	if (adev->wakeup.flags.valid)
+	if (adev->wakeup.flags.valid) {
+		if (pci_dev->bridge_d3)
+			device_wakeup_disable(dev);
+
 		device_set_wakeup_capable(dev, false);
+	}
 }
 
 static bool pci_acpi_bus_match(struct device *dev)