Fix acpi_memory_get_device().
A case of "memory object is not onlined at boot time but hot-added" is managed.


Signed-Off-By: KAMEZAWA Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>


Index: linux-2.6.14-mm1/drivers/acpi/acpi_memhotplug.c
===================================================================
--- linux-2.6.14-mm1.orig/drivers/acpi/acpi_memhotplug.c
+++ linux-2.6.14-mm1/drivers/acpi/acpi_memhotplug.c
@@ -77,6 +77,24 @@ struct acpi_memory_device {
 	u64 end_addr;		/* Memory Range end physical addr */
 };
 
+/* Maybe the same function in acpi_contaiener.c should be exported ..*/
+#define ACPI_STA_PRESENT                (0x00000001)
+static int is_memory_device_present(acpi_handle handle)
+{
+	acpi_status status;
+	unsigned long sta;
+	acpi_handle temp;
+	ACPI_FUNCTION_TRACE("is_memory_device_present");
+	status = acpi_get_handle(handle, "_STA", &temp);
+	if (ACPI_FAILURE(status))
+		return_VALUE(1);	/* _STA not found, assume present */
+	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+	if (ACPI_FAILURE(status))
+		return_VALUE(0);
+	return_VALUE((sta & ACPI_STA_PRESENT) == ACPI_STA_PRESENT);
+}
+
+
 static int
 acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
 {
@@ -112,18 +130,14 @@ acpi_memory_get_device_resources(struct 
 
 static int
 acpi_memory_get_device(acpi_handle handle,
-		       struct acpi_memory_device **mem_device)
+		       struct acpi_device **device)
 {
 	acpi_status status;
 	acpi_handle phandle;
-	struct acpi_device *device = NULL;
 	struct acpi_device *pdevice = NULL;
 
 	ACPI_FUNCTION_TRACE("acpi_memory_get_device");
 
-	if (!acpi_bus_get_device(handle, &device) && device)
-		goto end;
-
 	status = acpi_get_parent(handle, &phandle);
 	if (ACPI_FAILURE(status)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_get_parent\n"));
@@ -138,23 +152,12 @@ acpi_memory_get_device(acpi_handle handl
 		return_VALUE(-EINVAL);
 	}
 
-	/*
-	 * Now add the notified device.  This creates the acpi_device
-	 * and invokes .add function
-	 */
-	status = acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
+	status = acpi_bus_add(device, pdevice, handle, ACPI_BUS_TYPE_DEVICE);
 	if (ACPI_FAILURE(status)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error in acpi_bus_add\n"));
 		return_VALUE(-EINVAL);
 	}
 
-      end:
-	*mem_device = acpi_driver_data(device);
-	if (!(*mem_device)) {
-		printk(KERN_ERR "\n driver data not found");
-		return_VALUE(-ENODEV);
-	}
-
 	return_VALUE(0);
 }
 
@@ -282,9 +285,11 @@ static void acpi_memory_device_notify(ac
 {
 	struct acpi_memory_device *mem_device;
 	struct acpi_device *device;
+	acpi_status status;
+	int present;
 
 	ACPI_FUNCTION_TRACE("acpi_memory_device_notify");
-
+	present = is_memory_device_present(handle);
 	switch (event) {
 	case ACPI_NOTIFY_BUS_CHECK:
 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
@@ -294,12 +299,26 @@ static void acpi_memory_device_notify(ac
 		if (event == ACPI_NOTIFY_DEVICE_CHECK)
 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 					  "\nReceived DEVICE CHECK notification for device\n"));
-		if (acpi_memory_get_device(handle, &mem_device)) {
-			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+		status = acpi_bus_get_device(handle, &device);
+		if (ACPI_FAILURE(status) || !device) {
+			if (present) {
+				status = acpi_memory_get_device(handle, &device);
+				if (ACPI_FAILURE(status) || !device) {
+					ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 					  "Error in finding driver data\n"));
+					return_VOID;
+				}
+			} else {
+				ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+					"notified handle seems not present"));
+				return_VOID;
+			}
+		}
+		mem_device = acpi_driver_data(device);
+		if (!mem_device) {
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "error acpi_memhotplug: device has no mem_device"));
 			return_VOID;
 		}
-
 		if (!acpi_memory_check_device(mem_device)) {
 			if (acpi_memory_enable_device(mem_device))
 				ACPI_DEBUG_PRINT((ACPI_DB_ERROR,