On Fri, Jan 31, 2014 at 3:34 PM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> 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.
>
> Fixes: ef83b0781a73 (PCI: Remove from bus_list and release resources in pci_release_dev())
> Reported-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> 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..b8c93c90daf5 100644
> --- a/drivers/pci/remove.c
> +++ b/drivers/pci/remove.c
> @@ -3,6 +3,20 @@
> #include <linux/pci-aspm.h>
> #include "pci.h"
>
> +static void pci_free_resources(struct pci_dev *dev)
> +{
> + int i;
> +
> + msi_remove_pci_irq_vectors(dev);
looks like you are in a rush. Why do you put back msi_remove_pci_irq_vectors?
> +
> + 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 +39,11 @@ 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);
> }
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
