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* [PATCH] pci: make reset_subordinate hotplug safe
@ 2026-01-14 18:58 Keith Busch
  2026-01-14 19:18 ` Bjorn Helgaas
                   ` (3 more replies)
  0 siblings, 4 replies; 6+ messages in thread
From: Keith Busch @ 2026-01-14 18:58 UTC (permalink / raw)
  To: linux-pci, bhelgaas; +Cc: Keith Busch

From: Keith Busch <kbusch@kernel.org>

Use the slot reset method when resetting the bridge if the bus contains
hotplug slots. This fixes spurious hotplug events the secondary bus
reset triggers by utilizing slot's specific reset callback that ignores
link events.

Signed-off-by: Keith Busch <kbusch@kernel.org>
---
The new function introduced here is essentially the same as
pci_bus_error_reset, except it uses the reset functions that save and
restore the device. This is the same as before if not resetting a
hotplug slot.

 drivers/pci/pci-sysfs.c |  3 +--
 drivers/pci/pci.c       | 27 +++++++++++++++++++++++++++
 drivers/pci/pci.h       |  2 +-
 3 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 3881359440b1a..5c7c6f0c435f3 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -553,7 +553,6 @@ static ssize_t reset_subordinate_store(struct device *dev,
 				const char *buf, size_t count)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
-	struct pci_bus *bus = pdev->subordinate;
 	unsigned long val;
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -563,7 +562,7 @@ static ssize_t reset_subordinate_store(struct device *dev,
 		return -EINVAL;
 
 	if (val) {
-		int ret = __pci_reset_bus(bus);
+		int ret = pci_reset_bridge(pdev);
 
 		if (ret)
 			return ret;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b14dd064006cc..ca426ff68c820 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5747,6 +5747,33 @@ int __pci_reset_bus(struct pci_bus *bus)
 	return rc;
 }
 
+int pci_reset_bridge(struct pci_dev *bridge)
+{
+	struct pci_bus *bus = bridge->subordinate;
+	struct pci_slot *slot;
+
+	if (!bus)
+		return -ENOTTY;
+
+	mutex_lock(&pci_slot_mutex);
+	if (list_empty(&bus->slots))
+		goto bus_reset;
+
+	list_for_each_entry(slot, &bus->slots, list)
+		if (pci_probe_reset_slot(slot))
+			goto bus_reset;
+
+	list_for_each_entry(slot, &bus->slots, list)
+		if (__pci_reset_slot(slot))
+			goto bus_reset;
+
+	mutex_unlock(&pci_slot_mutex);
+	return 0;
+bus_reset:
+	mutex_unlock(&pci_slot_mutex);
+	return __pci_reset_bus(bus);
+}
+
 /**
  * pci_reset_bus - Try to reset a PCI bus
  * @pdev: top level PCI device to reset via slot/bus
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 36f8c0985430a..f216e7a37d726 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -197,7 +197,7 @@ bool pci_reset_supported(struct pci_dev *dev);
 void pci_init_reset_methods(struct pci_dev *dev);
 int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
 int pci_bus_error_reset(struct pci_dev *dev);
-int __pci_reset_bus(struct pci_bus *bus);
+int pci_reset_bridge(struct pci_dev *dev);
 
 struct pci_cap_saved_data {
 	u16		cap_nr;
-- 
2.47.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-01-15 17:38 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-01-14 18:58 [PATCH] pci: make reset_subordinate hotplug safe Keith Busch
2026-01-14 19:18 ` Bjorn Helgaas
2026-01-14 19:24   ` Keith Busch
2026-01-15 10:45 ` kernel test robot
2026-01-15 11:29 ` kernel test robot
2026-01-15 17:38 ` kernel test robot

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