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Merge branch 'pci/hotplug' 

- Fix pciehp AB-BA deadlock between reset_lock and device_lock (Lukas
  Wunner)

* pci/hotplug:
  PCI: pciehp: Fix AB-BA deadlock between reset_lock and device_lock
This commit is contained in:
Bjorn Helgaas 2023-04-20 16:16:33 -05:00
parent 66d3d0d0e8 f5eff5591b
commit 8745c3d542
1 changed files with 15 additions and 0 deletions
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15
drivers/pci/hotplug/pciehp_pci.c
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@ -63,7 +63,14 @@ int pciehp_configure_device(struct controller *ctrl)
pci_assign_unassigned_bridge_resources(bridge);
pcie_bus_configure_settings(parent);
/*
* Release reset_lock during driver binding
* to avoid AB-BA deadlock with device_lock.
*/
up_read(&ctrl->reset_lock);
pci_bus_add_devices(parent);
down_read_nested(&ctrl->reset_lock, ctrl->depth);
out:
pci_unlock_rescan_remove();
@ -104,7 +111,15 @@ void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
bus_list) {
pci_dev_get(dev);
/*
* Release reset_lock during driver unbinding
* to avoid AB-BA deadlock with device_lock.
*/
up_read(&ctrl->reset_lock);
pci_stop_and_remove_bus_device(dev);
down_read_nested(&ctrl->reset_lock, ctrl->depth);
/*
* Ensure that no new Requests will be generated from
* the device.