msi-wmi: rework init

There should be less code duplication with usage of gotos
Driver won't load if there's no hardware to control
Safer error handling at input driver allocation

Signed-off-by: Anisse Astier <anisse@astier.eu>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/platform/x86/msi-wmi.c b/drivers/platform/x86/msi-wmi.c
index fb988d8..dcb048c 100644 (file)
--- a/drivers/platform/x86/msi-wmi.c
+++ b/drivers/platform/x86/msi-wmi.c
@@ -284,6 +284,8 @@ static int __init msi_wmi_input_setup(void)
        int err;
 
        msi_wmi_input_dev = input_allocate_device();
+       if (!msi_wmi_input_dev)
+               return -ENOMEM;
 
        msi_wmi_input_dev->name = "MSI WMI hotkeys";
        msi_wmi_input_dev->phys = "wmi/input0";
@@ -314,40 +316,44 @@ static int __init msi_wmi_init(void)
 {
        int err;
 
-       if (wmi_has_guid(MSIWMI_EVENT_GUID)) {
-               err = wmi_install_notify_handler(MSIWMI_EVENT_GUID,
-                                                msi_wmi_notify, NULL);
-               if (err)
-                       return -EINVAL;
-
-               err = msi_wmi_input_setup();
-               if (err) {
-                       wmi_remove_notify_handler(MSIWMI_EVENT_GUID);
-                       return -EINVAL;
-               }
+       if (!wmi_has_guid(MSIWMI_EVENT_GUID)) {
+               printk(KERN_ERR
+                      "This machine doesn't have MSI-hotkeys through WMI\n");
+               return -ENODEV;
+       }
+       err = wmi_install_notify_handler(MSIWMI_EVENT_GUID,
+                       msi_wmi_notify, NULL);
+       if (err)
+               return -EINVAL;
 
-               if (!acpi_video_backlight_support()) {
-                       backlight = backlight_device_register(DRV_NAME,
-                                             NULL, NULL, &msi_backlight_ops);
-                       if (IS_ERR(backlight)) {
-                               wmi_remove_notify_handler(MSIWMI_EVENT_GUID);
-                               input_unregister_device(msi_wmi_input_dev);
-                               return -EINVAL;
-                       }
+       err = msi_wmi_input_setup();
+       if (err)
+               goto err_uninstall_notifier;
 
-                       backlight->props.max_brightness = ARRAY_SIZE(backlight_map) - 1;
-                       err = bl_get(NULL);
-                       if (err < 0) {
-                               wmi_remove_notify_handler(MSIWMI_EVENT_GUID);
-                               input_unregister_device(msi_wmi_input_dev);
-                               backlight_device_unregister(backlight);
-                               return -EINVAL;
-                       }
-                       backlight->props.brightness = err;
-               }
+       if (!acpi_video_backlight_support()) {
+               backlight = backlight_device_register(DRV_NAME,
+                               NULL, NULL, &msi_backlight_ops);
+               if (IS_ERR(backlight))
+                       goto err_free_input;
+
+               backlight->props.max_brightness = ARRAY_SIZE(backlight_map) - 1;
+               err = bl_get(NULL);
+               if (err < 0)
+                       goto err_free_backlight;
+
+               backlight->props.brightness = err;
        }
        printk(KERN_INFO DRV_PFX "Event handler installed\n");
+
        return 0;
+
+err_free_backlight:
+       backlight_device_unregister(backlight);
+err_free_input:
+       input_unregister_device(msi_wmi_input_dev);
+err_uninstall_notifier:
+       wmi_remove_notify_handler(MSIWMI_EVENT_GUID);
+       return err;
 }
 
 static void __exit msi_wmi_exit(void)