Commit bf4162bc authored by Darrick J. Wong's avatar Darrick J. Wong Committed by Jesse Barnes
Browse files

PCI hotplug: fakephp: Allocate PCI resources before adding the device 



For PCI devices, pci_bus_assign_resources() must be called to set up the
pci_device->resource array before pci_bus_add_devices() can be called, else
attempts to load drivers results in BAR collision errors where there are none.
This is not done in fakephp, so devices can be "unplugged" but scanning the
parent bus won't bring the devices back due to resource unallocation.  Move the
pci_bus_add_device-calling logic into pci_rescan_bus and preface it with a call
to pci_bus_assign_resources so that we only have to (re)allocate resources once
per bus where a new device is found.

Signed-off-by: default avatarDarrick J. Wong <djwong@us.ibm.com>
Acked-by: default avatarAlex Chiang <achiang@hp.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent bffac3c5

drivers/pci/hotplug/fakephp.c

+26 −16
Original line number Diff line number Diff line
@@ -195,13 +195,13 @@ static void remove_slot_worker(struct work_struct *work) 
 * Tries hard not to re-enable already existing devices;

 * also handles scanning of subfunctions.

 */

static void pci_rescan_slot(struct pci_dev *temp)

static int pci_rescan_slot(struct pci_dev *temp)

{

	struct pci_bus *bus = temp->bus;

	struct pci_dev *dev;

	int func;

	int retval;

	u8 hdr_type;

	int count = 0;



	if (!pci_read_config_byte(temp, PCI_HEADER_TYPE, &hdr_type)) {

		temp->hdr_type = hdr_type & 0x7f;
@@ -213,17 +213,12 @@ static void pci_rescan_slot(struct pci_dev *temp) 
				dbg("New device on %s function %x:%x\n",

					bus->name, temp->devfn >> 3,

					temp->devfn & 7);

				retval = pci_bus_add_device(dev);

				if (retval)

					dev_err(&dev->dev, "error adding "

						"device, continuing.\n");

				else

					add_slot(dev);

				count++;

			}

		}

		/* multifunction device? */

		if (!(hdr_type & 0x80))

			return;

			return count;



		/* continue scanning for other functions */

		for (func = 1, temp->devfn++; func < 8; func++, temp->devfn++) {
@@ -239,16 +234,13 @@ static void pci_rescan_slot(struct pci_dev *temp) 
					dbg("New device on %s function %x:%x\n",

						bus->name, temp->devfn >> 3,

						temp->devfn & 7);

					retval = pci_bus_add_device(dev);

					if (retval)

						dev_err(&dev->dev, "error adding "

							"device, continuing.\n");

					else

						add_slot(dev);

					count++;

				}

			}

		}

	}



	return count;

}
@@ -262,6 +254,8 @@ static void pci_rescan_bus(const struct pci_bus *bus) 
{

	unsigned int devfn;

	struct pci_dev *dev;

	int retval;

	int found = 0;

	dev = alloc_pci_dev();

	if (!dev)

		return;
@@ -270,7 +264,23 @@ static void pci_rescan_bus(const struct pci_bus *bus) 
	dev->sysdata = bus->sysdata;

	for (devfn = 0; devfn < 0x100; devfn += 8) {

		dev->devfn = devfn;

		pci_rescan_slot(dev);

		found += pci_rescan_slot(dev);

	}



	if (found) {

		pci_bus_assign_resources(bus);

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

			/* Skip already-added devices */

			if (dev->is_added)

					continue;

			retval = pci_bus_add_device(dev);

			if (retval)

				dev_err(&dev->dev,

					"Error adding device, continuing\n");

			else

				add_slot(dev);

		}

		pci_bus_add_devices(bus);

	}

	kfree(dev);

}

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