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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-02-01 15:38:29 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2014-02-01 10:24:31 -0800
commit04480094de7242d08bb62088e713fd7fe00443b4 (patch)
treea8a9806a3f55f5343b6375743c8e107e800c6df6
parent8a1f006ad302ea178aefb1f8c67e679c696289e9 (diff)
downloadlinux-linaro-stable-04480094de7242d08bb62088e713fd7fe00443b4.tar.gz
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>
-rw-r--r--drivers/pci/probe.c21
-rw-r--r--drivers/pci/remove.c17
2 files changed, 19 insertions, 19 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 04796c056d12..6e34498ec9f0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -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);
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 4ff36bfa785e..8bd76c9ba21c 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 @@ 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);
}