Commit cfcbfe5c authored by Keith Busch's avatar Keith Busch Committed by Bjorn Helgaas
Browse files

PCI: Don't fallback to bus reset after failed slot reset 



If a bus has hotplug slots that implement the slot's reset_slot callback,
it is not safe to do the non-slot specific bus reset, so don't fallback to
it. If a slot reset does fail, the subsequent bus reset will attempt a 2nd
link reset on top of previous and fail to handle the hotplug events.

Fixes: 8238cb69 ("PCI: Make reset_subordinate hotplug safe")
Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260421150644.3543733-1-kbusch@meta.com
parent 254f4963

drivers/pci/pci.c

+4 −5
Original line number Diff line number Diff line
@@ -5607,13 +5607,14 @@ static int pci_try_reset_bus(struct pci_bus *bus) 
 *           reset for affected devices

 *

 * This function will first try to reset the slots on this bus if the method is

 * available. If slot reset fails or is not available, this will fall back to a

 * available. If slot reset is not available, this will fall back to a

 * secondary bus reset.

 */

static int pci_reset_bridge(struct pci_dev *bridge, bool restore)

{

	struct pci_bus *bus = bridge->subordinate;

	struct pci_slot *slot;

	int ret = 0;



	if (!bus)

		return -ENOTTY;
@@ -5627,19 +5628,17 @@ static int pci_reset_bridge(struct pci_dev *bridge, bool restore) 
			goto bus_reset;



	list_for_each_entry(slot, &bus->slots, list) {

		int ret;



		if (restore)

			ret = pci_try_reset_slot(slot);

		else

			ret = pci_slot_reset(slot, PCI_RESET_DO_RESET);



		if (ret)

			goto bus_reset;

			break;

	}



	mutex_unlock(&pci_slot_mutex);

	return 0;

	return ret;

bus_reset:

	mutex_unlock(&pci_slot_mutex);