[ACPI] ACPICA 20051117

[pandora-kernel.git] / drivers / acpi / utilities / utmisc.c

diff --git a/drivers/acpi/utilities/utmisc.c b/drivers/acpi/utilities/utmisc.c
index 2a9110c..89efba7 100644 (file)
--- a/drivers/acpi/utilities/utmisc.c
+++ b/drivers/acpi/utilities/utmisc.c
@@ -63,6 +63,7 @@ ACPI_MODULE_NAME("utmisc")
 acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id)
 {
        acpi_native_uint i;
+       acpi_native_uint j;
        acpi_status status;
 
        ACPI_FUNCTION_TRACE("ut_allocate_owner_id");
@@ -82,29 +83,46 @@ acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id)
                return_ACPI_STATUS(status);
        }
 
-       /* Find a free owner ID */
+       /*
+        * Find a free owner ID, cycle through all possible IDs on repeated
+        * allocations. Note: Index for next possible ID is equal to the value
+        * of the last allocated ID.
+        */
+       for (i = 0, j = acpi_gbl_last_owner_id; i < 32; i++, j++) {
+               if (j >= 32) {
+                       j = 0;  /* Wraparound to ID start */
+               }
+
+               if (!(acpi_gbl_owner_id_mask & (1 << j))) {
+                       /*
+                        * Found a free ID. The actual ID is the bit index plus one,
+                        * making zero an invalid Owner ID. Save this as the last ID
+                        * allocated and update the global ID mask.
+                        */
+                       acpi_gbl_last_owner_id = (acpi_owner_id) (j + 1);
+                       *owner_id = acpi_gbl_last_owner_id;
 
-       for (i = 0; i < 32; i++) {
-               if (!(acpi_gbl_owner_id_mask & (1 << i))) {
                        ACPI_DEBUG_PRINT((ACPI_DB_VALUES,
                                          "Current owner_id mask: %8.8X New ID: %2.2X\n",
                                          acpi_gbl_owner_id_mask,
-                                         (unsigned int)(i + 1)));
+                                         (unsigned int)
+                                         acpi_gbl_last_owner_id));
 
-                       acpi_gbl_owner_id_mask |= (1 << i);
-                       *owner_id = (acpi_owner_id) (i + 1);
+                       acpi_gbl_owner_id_mask |= (1 << j);
                        goto exit;
                }
        }
 
        /*
-        * If we are here, all owner_ids have been allocated. This probably should
+        * All owner_ids have been allocated. This typically should
         * not happen since the IDs are reused after deallocation. The IDs are
         * allocated upon table load (one per table) and method execution, and
         * they are released when a table is unloaded or a method completes
         * execution.
+        *
+        * If this error happens, there may be very deep nesting of invoked control
+        * methods, or there may be a bug where the IDs are not released.
         */
-       *owner_id = 0;
        status = AE_OWNER_ID_LIMIT;
        ACPI_REPORT_ERROR(("Could not allocate new owner_id (32 max), AE_OWNER_ID_LIMIT\n"));