[PATCH] memory hotadd fixes: avoid registering res twice

both of acpi_memory_enable_device() and acpi_memory_add_device() may evaluate
_CRS method.

We should avoid evaluate device's resource twice if we could get it
successfully in past.

Signed-off-by: KAMEZWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Keith Mannthey <kmannth@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index e9175eaeb1df..b0d4b147b19e 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -129,11 +129,15 @@ acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
         struct acpi_memory_info *info, *n;
 
 
+        if (!list_empty(&mem_device->res_list))
+                return 0;
+
         status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
                                      acpi_memory_get_resource, mem_device);
         if (ACPI_FAILURE(status)) {
                 list_for_each_entry_safe(info, n, &mem_device->res_list, list)
                         kfree(info);
+                INIT_LIST_HEAD(&mem_device->res_list);
                 return -EINVAL;
         }