PCI/ACPI: Print info if host bridge notify handler installation fails

acpi_install_notify_handler() could fail.  So check the exit status
and give a better debug info.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 1389811aa21b..fd59f57d3829 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -769,6 +769,7 @@ static void handle_hotplug_event_root(acpi_handle handle, u32 type,
 static acpi_status __init
 find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
+        acpi_status status;
         char objname[64];
         struct acpi_buffer buffer = { .length = sizeof(objname),
                                       .pointer = objname };
@@ -781,9 +782,14 @@ find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 
         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 
-        acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
-                                handle_hotplug_event_root, NULL);
-        printk(KERN_DEBUG "acpi root: %s notify handler installed\n", objname);
+        status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+                                        handle_hotplug_event_root, NULL);
+        if (ACPI_FAILURE(status))
+                printk(KERN_DEBUG "acpi root: %s notify handler is not installed, exit status: %u\n",
+                                  objname, (unsigned int)status);
+        else
+                printk(KERN_DEBUG "acpi root: %s notify handler is installed\n",
+                                 objname);
 
         return AE_OK;
 }