ACPICA: Fix fault if acpi_terminate is called twice

Fixes a problem with the mechanism that prevents problems if the
acpi_terminate interface is inadvertently called more than once
before the ACPICA code is re-initialized. ACPICA BZ 795.

http://acpica.org/bugzilla/show_bug.cgi?id=795

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 15 insertions, 1 deletions

diff --git a/drivers/acpi/acpica/utxface.c b/drivers/acpi/acpica/utxface.c
index 078a22728c6b..483edbb3f441 100644
--- a/drivers/acpi/acpica/utxface.c
+++ b/drivers/acpi/acpica/utxface.c
@@ -318,7 +318,7 @@ ACPI_EXPORT_SYMBOL(acpi_initialize_objects)
  *
  * RETURN:      Status
  *
- * DESCRIPTION: Shutdown the ACPI subsystem.  Release all resources.
+ * DESCRIPTION: Shutdown the ACPICA subsystem and release all resources.
  *
  ******************************************************************************/
 acpi_status acpi_terminate(void)
@@ -327,6 +327,19 @@ acpi_status acpi_terminate(void)
 
         ACPI_FUNCTION_TRACE(acpi_terminate);
 
+        /* Just exit if subsystem is already shutdown */
+
+        if (acpi_gbl_shutdown) {
+                ACPI_ERROR((AE_INFO, "ACPI Subsystem is already terminated"));
+                return_ACPI_STATUS(AE_OK);
+        }
+
+        /* Subsystem appears active, go ahead and shut it down */
+
+        acpi_gbl_shutdown = TRUE;
+        acpi_gbl_startup_flags = 0;
+        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Shutting down ACPI Subsystem\n"));
+
         /* Terminate the AML Debugger if present */
 
         ACPI_DEBUGGER_EXEC(acpi_gbl_db_terminate_threads = TRUE);
@@ -353,6 +366,7 @@ acpi_status acpi_terminate(void)
 }
 
 ACPI_EXPORT_SYMBOL(acpi_terminate)
+
 #ifndef ACPI_ASL_COMPILER
 #ifdef ACPI_FUTURE_USAGE
 /*******************************************************************************