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: 8238cb69c01fe ("PCI: Make reset_subordinate hotplug safe")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260421150644.3543733-1-kbusch@meta.com

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8f7cfcc000901d8fce9b9589cf38cbdbb8bd2912..d34266651ad09f64f050062ebb7091ad1cf00e14 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -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);