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Revert "PCI: Remove from bus_list and release resources in pci_release_dev()" 

Revert commit ef83b0781a "PCI: Remove from bus_list and release
resources in pci_release_dev()" that made some nasty race conditions
become possible.  For example, if a Thunderbolt link is unplugged
and then replugged immediately, the pci_release_dev() resulting from
the hot-remove code path may be racing with the hot-add code path
which after that commit causes various kinds of breakage to happen
(up to and including a hard crash of the whole system).

Moreover, the problem that commit ef83b0781a attempted to address
cannot happen any more after commit 8a4c5c329d "PCI: Check parent
kobject in pci_destroy_dev()", because pci_destroy_dev() will now
return immediately if it has already been executed for the given
device.

Note, however, that the invocation of msi_remove_pci_irq_vectors()
removed by commit ef83b0781a from pci_free_resources() along with
the other changes made by it is not added back because of subsequent
code changes depending on that modification.

Fixes: ef83b0781a (PCI: Remove from bus_list and release resources in pci_release_dev())
Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Rafael J. Wysocki 2014-02-01 15:38:29 +01:00 committed by Linus Torvalds
parent 8a1f006ad3
commit 04480094de
2 changed files with 19 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/pci/probe.c
View File

@ -1208,18 +1208,6 @@ static void pci_release_capabilities(struct pci_dev *dev)
pci_free_cap_save_buffers(dev);
}
static void pci_free_resources(struct pci_dev *dev)
{
int i;
pci_cleanup_rom(dev);
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *res = dev->resource + i;
if (res->parent)
release_resource(res);
}
}
/**
* pci_release_dev - free a pci device structure when all users of it are finished.
* @dev: device that's been disconnected
@ -1229,14 +1217,9 @@ static void pci_free_resources(struct pci_dev *dev)
*/
static void pci_release_dev(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
down_write(&pci_bus_sem);
list_del(&pci_dev->bus_list);
up_write(&pci_bus_sem);
pci_free_resources(pci_dev);
struct pci_dev *pci_dev;
pci_dev = to_pci_dev(dev);
pci_release_capabilities(pci_dev);
pci_release_of_node(pci_dev);
pcibios_release_device(pci_dev);

17
drivers/pci/remove.c
View File

@ -3,6 +3,18 @@
#include <linux/pci-aspm.h>
#include "pci.h"
static void pci_free_resources(struct pci_dev *dev)
{
int i;
pci_cleanup_rom(dev);
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *res = dev->resource + i;
if (res->parent)
release_resource(res);
}
}
static void pci_stop_dev(struct pci_dev *dev)
{
pci_pme_active(dev, false);
@ -25,6 +37,11 @@ static void pci_destroy_dev(struct pci_dev *dev)
device_del(&dev->dev);
down_write(&pci_bus_sem);
list_del(&dev->bus_list);
up_write(&pci_bus_sem);
pci_free_resources(dev);
put_device(&dev->dev);
}