Commit 8745c3d5 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

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
parents 66d3d0d0 f5eff559

drivers/pci/hotplug/pciehp_pci.c

+15 −0
Original line number Diff line number Diff line
@@ -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.