[PATCH 2/2] pci: fix slot reset device locking

[Keith Busch <kbusch@meta.com>]

From: Keith Busch <kbusch@kernel.org>

Like pci_bus_lock, pci_slot_lock needs to lock the bridge device to
prevent the warning:

  pcieport 0000:e2:05.0: unlocked secondary bus reset via: pciehp_reset_slot+0x55/0xa0

Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 drivers/pci/pci.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 3378221c5723a..5f8b0d06a1459 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5460,6 +5460,8 @@ static void pci_slot_lock(struct pci_slot *slot)
 {
 	struct pci_dev *dev;
 
+	if (slot->bus->self)
+		pci_dev_lock(slot->bus->self);
 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
 		if (!dev->slot || dev->slot != slot)
 			continue;
@@ -5483,12 +5485,17 @@ static void pci_slot_unlock(struct pci_slot *slot)
 		else
 			pci_dev_unlock(dev);
 	}
+	if (slot->bus->self)
+		pci_dev_unlock(slot->bus->self);
 }
 
 /* Return 1 on successful lock, 0 on contention */
 static int pci_slot_trylock(struct pci_slot *slot)
 {
-	struct pci_dev *dev;
+	struct pci_dev *dev, *bridge = slot->bus->self;
+
+	if (bridge && !pci_dev_trylock(bridge))
+		return 0;
 
 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
 		if (!dev->slot || dev->slot != slot)
@@ -5511,6 +5518,9 @@ static int pci_slot_trylock(struct pci_slot *slot)
 		else
 			pci_dev_unlock(dev);
 	}
+
+	if (bridge)
+		pci_dev_unlock(bridge);
 	return 0;
 }
 
-- 
2.47.3