1 files changed, 26 insertions, 8 deletions

diff --git a/drivers/acpi/utilities/utmisc.c b/drivers/acpi/utilities/utmisc.c
index 2a9110c06391..89efba7bf449 100644
--- 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"));