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>

1 files changed, 35 insertions, 29 deletions

diff --git a/drivers/platform/x86/msi-wmi.c b/drivers/platform/x86/msi-wmi.c
index fb988d8f4267..dcb048c0793f 100644
--- 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)