Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 04480094 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

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



Revert commit ef83b078 "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 ef83b078 attempted to address
cannot happen any more after commit 8a4c5c32 "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 ef83b078 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: ef83b078 (PCI: Remove from bus_list and release resources in pci_release_dev())
Reported-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8a1f006a

drivers/pci/probe.c

+2 −19
Original line number Diff line number Diff line
@@ -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);

drivers/pci/remove.c

+17 −0
Original line number Diff line number Diff line
@@ -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);

}