Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c12ff1df authored by Yu Zhao's avatar Yu Zhao Committed by Jesse Barnes
Browse files

PCI: support Secondary Bus Reset 



PCI-to-PCI Bridge 1.2 specifies that the Secondary Bus Reset bit can
force the assertion of RST# on the secondary interface, which can be
used to reset all devices including subordinates under this bus. This
can be used to reset a function if this function is the only device
under this bus.

Reviewed-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarYu Zhao <yu.zhao@intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent f85876ba

drivers/pci/pci.c

+31 −0
Original line number Original line Diff line number Diff line
@@ -2162,6 +2162,33 @@ static int pci_pm_reset(struct pci_dev *dev, int probe) 
	return 0;

	return 0;

}

}





static int pci_parent_bus_reset(struct pci_dev *dev, int probe)

{

	u16 ctrl;

	struct pci_dev *pdev;



	if (dev->subordinate)

		return -ENOTTY;



	list_for_each_entry(pdev, &dev->bus->devices, bus_list)

		if (pdev != dev)

			return -ENOTTY;



	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);



	return 0;

}



static int pci_dev_reset(struct pci_dev *dev, int probe)

static int pci_dev_reset(struct pci_dev *dev, int probe)

{

{

	int rc;

	int rc;
@@ -2183,6 +2210,10 @@ static int pci_dev_reset(struct pci_dev *dev, int probe) 
		goto done;

		goto done;





	rc = pci_pm_reset(dev, probe);

	rc = pci_pm_reset(dev, probe);

	if (rc != -ENOTTY)

		goto done;



	rc = pci_parent_bus_reset(dev, probe);

done:

done:

	if (!probe) {

	if (!probe) {

		up(&dev->dev.sem);

		up(&dev->dev.sem);