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>

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 1389811..fd59f57 100644 (file)
--- 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;
 }