Revert "PCI: Remove from bus_list and release resources in pci_release_dev()"
Revert commit ef83b0781a73 "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 ef83b0781a73 attempted to address
cannot happen any more after commit 8a4c5c329de7 "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 ef83b0781a73 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: ef83b0781a73 (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>
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 04796c0..6e34498 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1208,18 +1208,6 @@
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_release_dev(struct device *dev)
{
- struct pci_dev *pci_dev = to_pci_dev(dev);
+ struct pci_dev *pci_dev;
- down_write(&pci_bus_sem);
- list_del(&pci_dev->bus_list);
- up_write(&pci_bus_sem);
-
- pci_free_resources(pci_dev);
-
+ pci_dev = to_pci_dev(dev);
pci_release_capabilities(pci_dev);
pci_release_of_node(pci_dev);
pcibios_release_device(pci_dev);
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 4ff36bf..8bd76c9 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -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 @@
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);
}
