Commit ce29ca3e authored by Amos Kong's avatar Amos Kong Committed by Bjorn Helgaas
Browse files

PCI: acpiphp: remove all functions in slot, even without ACPI _EJx 

When we add a device with acpiphp, we enumerate all functions in the
slot with pci_scan_slot(), regardless of whether they have associated
ACPI methods such as _EJ0.

When removing the device, we previously removed only the functions
with those ACPI methods.  This patch makes the remove symmetric with the
add: we remove all functions in the slot, whether they have associated
ACPI methods or not.

With qemu-kvm and SeaBIOS, we can build a multi-function device where
only function 0 has _EJ0 and _ADR (see bugzilla below).  Removing and
re-adding that slot (including all functions of the device) works correctly
with Windows guests.  This patch makes it also work in Linux guests.

[bhelgaas: restructure loop iteration, pull out of slot->funcs loop]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=43219


Signed-off-by: default avatarAmos Kong <kongjianjun@gmail.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 638f2933

drivers/pci/hotplug/acpiphp_glue.c

+32 −10
Original line number Diff line number Diff line
@@ -878,6 +878,24 @@ static void disable_bridges(struct pci_bus *bus) 
	}

}



/* return first device in slot, acquiring a reference on it */

static struct pci_dev *dev_in_slot(struct acpiphp_slot *slot)

{

	struct pci_bus *bus = slot->bridge->pci_bus;

	struct pci_dev *dev;

	struct pci_dev *ret = NULL;



	down_read(&pci_bus_sem);

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

		if (PCI_SLOT(dev->devfn) == slot->device) {

			ret = pci_dev_get(dev);

			break;

		}

	up_read(&pci_bus_sem);



	return ret;

}



/**

 * disable_device - disable a slot

 * @slot: ACPI PHP slot
@@ -902,10 +920,15 @@ static int disable_device(struct acpiphp_slot *slot) 
						(u32)1, NULL, NULL);

			func->bridge = NULL;

		}

	}



		pdev = pci_get_slot(slot->bridge->pci_bus,

				    PCI_DEVFN(slot->device, func->function));

		if (pdev) {

	/*

	 * enable_device() enumerates all functions in this device via

	 * pci_scan_slot(), whether they have associated ACPI hotplug

	 * methods (_EJ0, etc.) or not.  Therefore, we remove all functions

	 * here.

	 */

	while ((pdev = dev_in_slot(slot))) {

		pci_stop_bus_device(pdev);

		if (pdev->subordinate) {

			disable_bridges(pdev->subordinate);
@@ -914,7 +937,6 @@ static int disable_device(struct acpiphp_slot *slot) 
		__pci_remove_bus_device(pdev);

		pci_dev_put(pdev);

	}

	}



	list_for_each_entry(func, &slot->funcs, sibling) {

		acpiphp_bus_trim(func->handle);

drivers/pci/search.c

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
#include "pci.h"



DECLARE_RWSEM(pci_bus_sem);

EXPORT_SYMBOL_GPL(pci_bus_sem);



/*

 * find the upstream PCIe-to-PCI bridge of a PCI device

 * if the device is PCIE, return NULL

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