1 files changed, 33 insertions, 4 deletions

diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index f9033e190fb6..e0610bda1dea 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -57,6 +57,22 @@ __setup("pcie_ports=", pcie_port_setup);
 
 /* global data */
 
+/**
+ * pcie_clear_root_pme_status - Clear root port PME interrupt status.
+ * @dev: PCIe root port or event collector.
+ */
+void pcie_clear_root_pme_status(struct pci_dev *dev)
+{
+        int rtsta_pos;
+        u32 rtsta;
+
+        rtsta_pos = pci_pcie_cap(dev) + PCI_EXP_RTSTA;
+
+        pci_read_config_dword(dev, rtsta_pos, &rtsta);
+        rtsta |= PCI_EXP_RTSTA_PME;
+        pci_write_config_dword(dev, rtsta_pos, rtsta);
+}
+
 static int pcie_portdrv_restore_config(struct pci_dev *dev)
 {
         int retval;
@@ -69,6 +85,20 @@ static int pcie_portdrv_restore_config(struct pci_dev *dev)
 }
 
 #ifdef CONFIG_PM
+static int pcie_port_resume_noirq(struct device *dev)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+
+        /*
+         * Some BIOSes forget to clear Root PME Status bits after system wakeup
+         * which breaks ACPI-based runtime wakeup on PCI Express, so clear those
+         * bits now just in case (shouldn't hurt).
+         */
+        if(pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT)
+                pcie_clear_root_pme_status(pdev);
+        return 0;
+}
+
 static const struct dev_pm_ops pcie_portdrv_pm_ops = {
         .suspend        = pcie_port_device_suspend,
         .resume         = pcie_port_device_resume,
@@ -76,6 +106,7 @@ static const struct dev_pm_ops pcie_portdrv_pm_ops = {
         .thaw           = pcie_port_device_resume,
         .poweroff       = pcie_port_device_suspend,
         .restore        = pcie_port_device_resume,
+        .resume_noirq   = pcie_port_resume_noirq,
 };
 
 #define PCIE_PORTDRV_PM_OPS     (&pcie_portdrv_pm_ops)
@@ -327,10 +358,8 @@ static int __init pcie_portdrv_init(void)
 {
         int retval;
 
-        if (pcie_ports_disabled) {
-                pcie_no_aspm();
-                return -EACCES;
-        }
+        if (pcie_ports_disabled)
+                return pci_register_driver(&pcie_portdriver);
 
         dmi_check_system(pcie_portdrv_dmi_table);