diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
index 916ccb2b316c..1b1dddbd5744 100644
--- a/drivers/platform/x86/dell-wmi.c
+++ b/drivers/platform/x86/dell-wmi.c
@@ -202,8 +202,13 @@ static void dell_wmi_notify(u32 value, void *context)
 	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
 	static struct key_entry *key;
 	union acpi_object *obj;
+	acpi_status status;
 
-	wmi_get_event_data(value, &response);
+	status = wmi_get_event_data(value, &response);
+	if (status != AE_OK) {
+		printk(KERN_INFO "dell-wmi: bad event status 0x%x\n", status);
+		return;
+	}
 
 	obj = (union acpi_object *)response.pointer;
 
@@ -323,8 +328,9 @@ static int __init dell_wmi_input_setup(void)
 static int __init dell_wmi_init(void)
 {
 	int err;
+	acpi_status status;
 
-	if (wmi_has_guid(DELL_EVENT_GUID)) {
+	if (!wmi_has_guid(DELL_EVENT_GUID)) {
 		printk(KERN_WARNING "dell-wmi: No known WMI GUID found\n");
 		return -ENODEV;
 	}
@@ -336,14 +342,14 @@ static int __init dell_wmi_init(void)
 	if (err)
 		return err;
 
-	err = wmi_install_notify_handler(DELL_EVENT_GUID,
+	status = wmi_install_notify_handler(DELL_EVENT_GUID,
 					 dell_wmi_notify, NULL);
-	if (err) {
+	if (ACPI_FAILURE(status)) {
 		input_unregister_device(dell_wmi_input_dev);
 		printk(KERN_ERR
 			"dell-wmi: Unable to register notify handler - %d\n",
-			err);
-		return err;
+			status);
+		return -ENODEV;
 	}
 
 	return 0;
diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
index 8781d8fa7a57..5b648f0c6075 100644
--- a/drivers/platform/x86/hp-wmi.c
+++ b/drivers/platform/x86/hp-wmi.c
@@ -338,8 +338,13 @@ static void hp_wmi_notify(u32 value, void *context)
 	static struct key_entry *key;
 	union acpi_object *obj;
 	int eventcode;
+	acpi_status status;
 
-	wmi_get_event_data(value, &response);
+	status = wmi_get_event_data(value, &response);
+	if (status != AE_OK) {
+		printk(KERN_INFO "hp-wmi: bad event status 0x%x\n", status);
+		return;
+	}
 
 	obj = (union acpi_object *)response.pointer;
 
@@ -581,7 +586,7 @@ static int __init hp_wmi_init(void)
 	if (wmi_has_guid(HPWMI_EVENT_GUID)) {
 		err = wmi_install_notify_handler(HPWMI_EVENT_GUID,
 						 hp_wmi_notify, NULL);
-		if (!err)
+		if (ACPI_SUCCESS(err))
 			hp_wmi_input_setup();
 	}
 
diff --git a/drivers/platform/x86/msi-wmi.c b/drivers/platform/x86/msi-wmi.c
index 7f77f908bb01..f5f70d4c6913 100644
--- a/drivers/platform/x86/msi-wmi.c
+++ b/drivers/platform/x86/msi-wmi.c
@@ -149,8 +149,13 @@ static void msi_wmi_notify(u32 value, void *context)
 	static struct key_entry *key;
 	union acpi_object *obj;
 	ktime_t cur;
+	acpi_status status;
 
-	wmi_get_event_data(value, &response);
+	status = wmi_get_event_data(value, &response);
+	if (status != AE_OK) {
+		printk(KERN_INFO DRV_PFX "bad event status 0x%x\n", status);
+		return;
+	}
 
 	obj = (union acpi_object *)response.pointer;
 
@@ -236,7 +241,7 @@ static int __init msi_wmi_init(void)
 	}
 	err = wmi_install_notify_handler(MSIWMI_EVENT_GUID,
 			msi_wmi_notify, NULL);
-	if (err)
+	if (ACPI_FAILURE(err))
 		return -EINVAL;
 
 	err = msi_wmi_input_setup();
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 9f93d6c0f510..b104302fea0a 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -492,8 +492,7 @@ wmi_notify_handler handler, void *data)
 	if (!guid || !handler)
 		return AE_BAD_PARAMETER;
 
-	find_guid(guid, &block);
-	if (!block)
+	if (!find_guid(guid, &block))
 		return AE_NOT_EXIST;
 
 	if (block->handler)
@@ -521,8 +520,7 @@ acpi_status wmi_remove_notify_handler(const char *guid)
 	if (!guid)
 		return AE_BAD_PARAMETER;
 
-	find_guid(guid, &block);
-	if (!block)
+	if (!find_guid(guid, &block))
 		return AE_NOT_EXIST;
 
 	if (!block->handler)
@@ -716,6 +714,22 @@ static int wmi_class_init(void)
 	return ret;
 }
 
+static bool guid_already_parsed(const char *guid_string)
+{
+	struct guid_block *gblock;
+	struct wmi_block *wblock;
+	struct list_head *p;
+
+	list_for_each(p, &wmi_blocks.list) {
+		wblock = list_entry(p, struct wmi_block, list);
+		gblock = &wblock->gblock;
+
+		if (strncmp(gblock->guid, guid_string, 16) == 0)
+			return true;
+	}
+	return false;
+}
+
 /*
  * Parse the _WDG method for the GUID data blocks
  */
@@ -725,6 +739,7 @@ static __init acpi_status parse_wdg(acpi_handle handle)
 	union acpi_object *obj;
 	struct guid_block *gblock;
 	struct wmi_block *wblock;
+	char guid_string[37];
 	acpi_status status;
 	u32 i, total;
 
@@ -747,6 +762,19 @@ static __init acpi_status parse_wdg(acpi_handle handle)
 	memcpy(gblock, obj->buffer.pointer, obj->buffer.length);
 
 	for (i = 0; i < total; i++) {
+		/*
+		  Some WMI devices, like those for nVidia hooks, have a
+		  duplicate GUID. It's not clear what we should do in this
+		  case yet, so for now, we'll just ignore the duplicate.
+		  Anyone who wants to add support for that device can come
+		  up with a better workaround for the mess then.
+		*/
+		if (guid_already_parsed(gblock[i].guid) == true) {
+			wmi_gtoa(gblock[i].guid, guid_string);
+			printk(KERN_INFO PREFIX "Skipping duplicate GUID %s\n",
+				guid_string);
+			continue;
+		}
 		wblock = kzalloc(sizeof(struct wmi_block), GFP_KERNEL);
 		if (!wblock)
 			return AE_NO_MEMORY;