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-rw-r--r--drivers/pci/hotplug/acpiphp_glue.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index fa8fe7441952..91276f9fe268 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -651,6 +651,17 @@ static unsigned int get_slot_status(struct acpiphp_slot *slot)
 	return (unsigned int)sta;
 }
 
+static inline bool device_status_valid(unsigned int sta)
+{
+	/*
+	 * ACPI spec says that _STA may return bit 0 clear with bit 3 set
+	 * if the device is valid but does not require a device driver to be
+	 * loaded (Section 6.3.7 of ACPI 5.0A).
+	 */
+	unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
+	return (sta & mask) == mask;
+}
+
 /**
  * trim_stale_devices - remove PCI devices that are not responding.
  * @dev: PCI device to start walking the hierarchy from.
@@ -666,7 +677,7 @@ static void trim_stale_devices(struct pci_dev *dev)
 		unsigned long long sta;
 
 		status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
-		alive = (ACPI_SUCCESS(status) && sta == ACPI_STA_ALL)
+		alive = (ACPI_SUCCESS(status) && device_status_valid(sta))
 			|| acpiphp_no_hotplug(adev);
 	}
 	if (!alive) {
@@ -712,7 +723,7 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
 
 		if (slot_no_hotplug(slot)) {
 			; /* do nothing */
-		} else if (get_slot_status(slot) == ACPI_STA_ALL) {
+		} else if (device_status_valid(get_slot_status(slot))) {
 			/* remove stale devices if any */
 			list_for_each_entry_safe_reverse(dev, tmp,
 							 &bus->devices, bus_list)