[PATCH] pci: don't fallback to bus reset after failed slot reset

[PATCH] pci: don't fallback to bus reset after failed slot reset

[Keith Busch]

From: Keith Busch <kbusch@kernel.org>

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>
---
 drivers/pci/pci.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8f7cfcc000901..d34266651ad09 100644
--- 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);
 
-- 
2.52.0