From 04480094de7242d08bb62088e713fd7fe00443b4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 1 Feb 2014 15:38:29 +0100 Subject: 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 Signed-off-by: Rafael J. Wysocki Signed-off-by: Linus Torvalds --- drivers/pci/probe.c | 21 ++------------------- drivers/pci/remove.c | 17 +++++++++++++++++ 2 files changed, 19 insertions(+), 19 deletions(-) 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 @@ 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 4ff36bf..8bd76c9 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -3,6 +3,18 @@ #include #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); } -- cgit v1.1