diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e37fea6e178d..d46860898e1f 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3215,9 +3215,30 @@ static int pci_pm_reset(struct pci_dev *dev, int probe) return 0; } -static int pci_parent_bus_reset(struct pci_dev *dev, int probe) +/** + * pci_reset_bridge_secondary_bus - Reset the secondary bus on a PCI bridge. + * @dev: Bridge device + * + * Use the bridge control register to assert reset on the secondary bus. + * Devices on the secondary bus are left in power-on state. + */ +void pci_reset_bridge_secondary_bus(struct pci_dev *dev) { u16 ctrl; + + pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl); + ctrl |= PCI_BRIDGE_CTL_BUS_RESET; + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); + msleep(100); + + ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); + msleep(100); +} +EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus); + +static int pci_parent_bus_reset(struct pci_dev *dev, int probe) +{ struct pci_dev *pdev; if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self) @@ -3230,14 +3251,7 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe) if (probe) return 0; - pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, &ctrl); - ctrl |= PCI_BRIDGE_CTL_BUS_RESET; - pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl); - msleep(100); - - ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; - pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl); - msleep(100); + pci_reset_bridge_secondary_bus(dev->bus->self); return 0; } diff --git a/include/linux/pci.h b/include/linux/pci.h index 0fd1f1582fa1..35c1bc4909f3 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -924,6 +924,7 @@ int pcie_set_mps(struct pci_dev *dev, int mps); int __pci_reset_function(struct pci_dev *dev); int __pci_reset_function_locked(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev); +void pci_reset_bridge_secondary_bus(struct pci_dev *dev); void pci_update_resource(struct pci_dev *dev, int resno); int __must_check pci_assign_resource(struct pci_dev *dev, int i); int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align);