diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 313f959..edc970d 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -917,8 +917,10 @@ static int acpi_video_bus_check(struct acpi_video_bus *video)
 		return -EINVAL;
 
 	dev = acpi_get_pci_dev(video->device->handle);
-	if (!dev)
+	if (!dev) {
+		dev_info(&video->device->dev, "%s: 2\n", __func__);
 		return -ENODEV;
+	}
 	pci_dev_put(dev);
 
 	/* Since there is no HID, CID and so on for VGA driver, we have
@@ -1374,7 +1376,7 @@ acpi_video_bus_get_devices(struct acpi_video_bus *video,
 		status = acpi_video_bus_get_one_device(dev, video);
 		if (status) {
 			printk(KERN_WARNING PREFIX
-					"Can't attach device\n");
+					"%s: Can't attach device, status=0x%x\n", __func__, status);
 			continue;
 		}
 	}
@@ -1643,10 +1645,13 @@ static int acpi_video_bus_add(struct acpi_device *device)
 		if (!allow_duplicates)
 			return -ENODEV;
 	}
+	dev_info(&device->dev, "%s: status=0x%x\n", __func__, status);
 
 	video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
-	if (!video)
+	if (!video) {
+		dev_info(&device->dev, "%s: 1\n", __func__);
 		return -ENOMEM;
+	}
 
 	/* a hack to fix the duplicate name "VID" problem on T61 */
 	if (!strcmp(device->pnp.bus_id, "VID")) {
@@ -1668,25 +1673,32 @@ static int acpi_video_bus_add(struct acpi_device *device)
 
 	acpi_video_bus_find_cap(video);
 	error = acpi_video_bus_check(video);
-	if (error)
+	if (error) {
+		dev_info(&device->dev, "%s: 3, err=0x%x\n", __func__, error);
 		goto err_free_video;
+	}
 
 	mutex_init(&video->device_list_lock);
 	INIT_LIST_HEAD(&video->video_device_list);
 
 	error = acpi_video_bus_get_devices(video, device);
-	if (error)
+	if (error) {
+		dev_info(&device->dev, "%s: 4, err=0x%x\n", __func__, error);
 		goto err_free_video;
+	}
 
 	video->input = input = input_allocate_device();
 	if (!input) {
+		dev_info(&device->dev, "%s: 5\n", __func__);
 		error = -ENOMEM;
 		goto err_put_video;
 	}
 
 	error = acpi_video_bus_start_devices(video);
-	if (error)
+	if (error) {
+		dev_info(&device->dev, "%s: 6, err=0x%x\n", __func__, error);
 		goto err_free_input_dev;
+	}
 
 	snprintf(video->phys, sizeof(video->phys),
 		"%s/video/input0", acpi_device_hid(video->device));
@@ -1715,12 +1727,16 @@ static int acpi_video_bus_add(struct acpi_device *device)
 	video->pm_nb.notifier_call = acpi_video_resume;
 	video->pm_nb.priority = 0;
 	error = register_pm_notifier(&video->pm_nb);
-	if (error)
+	if (error) {
+		dev_info(&device->dev, "%s: 7, err=0x%x\n", __func__, error);
 		goto err_stop_video;
+	}
 
 	error = input_register_device(input);
-	if (error)
+	if (error) {
+		dev_info(&device->dev, "%s: 8, err=0x%x\n", __func__, error);
 		goto err_unregister_pm_notifier;
+	}
 
 	return 0;
 
@@ -1797,6 +1813,7 @@ int acpi_video_register(void)
 {
 	int result = 0;
 	if (register_count) {
+		pr_info("%s: already registered\n", __func__);
 		/*
 		 * if the function of acpi_video_register is already called,
 		 * don't register the acpi_vide_bus again and return no error.