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PCI: Add pci_reset_bridge_secondary_bus()

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Move the secondary bus reset code from pci_parent_bus_reset() into its own
function.  Export it as we'll later be calling it from hotplug controllers
and elsewhere.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Alex Williamson
2013-08-08 14:09:24 -06:00
committed by Bjorn Helgaas
parent 3b2f64d00c
commit 64e8674fbe
2 changed files with 24 additions and 9 deletions
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32
drivers/pci/pci.c
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@@ -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;
}