1 files changed, 17 insertions, 6 deletions

diff --git a/drivers/acpi/events/evxface.c b/drivers/acpi/events/evxface.c
index 6d866a01f5f4..94a6efe020be 100644
--- a/drivers/acpi/events/evxface.c
+++ b/drivers/acpi/events/evxface.c
@@ -5,7 +5,7 @@
  *****************************************************************************/
 
 /*
- * Copyright (C) 2000 - 2007, R. Byron Moore
+ * Copyright (C) 2000 - 2008, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -758,6 +758,12 @@ ACPI_EXPORT_SYMBOL(acpi_remove_gpe_handler)
  *
  * DESCRIPTION: Acquire the ACPI Global Lock
  *
+ * Note: Allows callers with the same thread ID to acquire the global lock
+ * multiple times. In other words, externally, the behavior of the global lock
+ * is identical to an AML mutex. On the first acquire, a new handle is
+ * returned. On any subsequent calls to acquire by the same thread, the same
+ * handle is returned.
+ *
  ******************************************************************************/
 acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
 {
@@ -770,14 +776,19 @@ acpi_status acpi_acquire_global_lock(u16 timeout, u32 * handle)
         /* Must lock interpreter to prevent race conditions */
 
         acpi_ex_enter_interpreter();
-        status = acpi_ev_acquire_global_lock(timeout);
-        acpi_ex_exit_interpreter();
+
+        status = acpi_ex_acquire_mutex_object(timeout,
+                                              acpi_gbl_global_lock_mutex,
+                                              acpi_os_get_thread_id());
 
         if (ACPI_SUCCESS(status)) {
-                acpi_gbl_global_lock_handle++;
+
+                /* Return the global lock handle (updated in acpi_ev_acquire_global_lock) */
+
                 *handle = acpi_gbl_global_lock_handle;
         }
 
+        acpi_ex_exit_interpreter();
         return (status);
 }
 
@@ -798,11 +809,11 @@ acpi_status acpi_release_global_lock(u32 handle)
 {
         acpi_status status;
 
-        if (handle != acpi_gbl_global_lock_handle) {
+        if (!handle || (handle != acpi_gbl_global_lock_handle)) {
                 return (AE_NOT_ACQUIRED);
         }
 
-        status = acpi_ev_release_global_lock();
+        status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
         return (status);
 }