Merge branch 'pci/reset'

- Log debug messages about reset methods being used (Bjorn Helgaas)

- Avoid reset when it has been disabled via sysfs (Nishanth Aravamudan)

* pci/reset:
  PCI: Avoid reset when disabled via sysfs
  PCI: Log debug messages about reset method

Author: bjorn-helgaas

drivers/pci/pci.c

@@ -5249,6 +5249,7 @@ const struct pci_reset_fn_method pci_reset_fn_methods[] = {
 int __pci_reset_function_locked(struct pci_dev *dev)
 {
 	int i, m, rc;
+	const struct pci_reset_fn_method *method;
 
 	might_sleep();
 
@@ -5265,9 +5266,13 @@ int __pci_reset_function_locked(struct pci_dev *dev)
 		if (!m)
 			return -ENOTTY;
 
-		rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_DO_RESET);
+		method = &pci_reset_fn_methods[m];
+		pci_dbg(dev, "reset via %s\n", method->name);
+		rc = method->reset_fn(dev, PCI_RESET_DO_RESET);
 		if (!rc)
 			return 0;
+
+		pci_dbg(dev, "%s failed with %d\n", method->name, rc);
 		if (rc != -ENOTTY)
 			return rc;
 	}
@@ -5424,6 +5429,8 @@ static bool pci_bus_resettable(struct pci_bus *bus)
 		return false;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
+		if (!pci_reset_supported(dev))
+			return false;
 		if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
 		    (dev->subordinate && !pci_bus_resettable(dev->subordinate)))
 			return false;
@@ -5500,6 +5507,8 @@ static bool pci_slot_resettable(struct pci_slot *slot)
 	list_for_each_entry(dev, &slot->bus->devices, bus_list) {
 		if (!dev->slot || dev->slot != slot)
 			continue;
+		if (!pci_reset_supported(dev))
+			return false;
 		if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
 		    (dev->subordinate && !pci_bus_resettable(dev->subordinate)))
 			return false;